Question:

Trying again to help my 8th grade daughter with algebra...simplify each expression: -w+4(w+3) I don't just ?

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want answers...I want to know how you got it...5(b+4)-6b...-4x+3(2x-5)

2(3a+2)...-4+2(3+d)

I think if I had a little explanation I could figure out the rest...but it's been a long time since I did 8th grade algebra.

HELP!!

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  1. 1.  5(b+4) is equivalent to  (5)(b) + (5)(4).  You multiply each item in the parenthesis by the 5.   That leaves you with 5b+20.  Then it is simple algebra from here.  

    Subtract 20 from each side to isolate 5b

    5b +20 -20 = 0 -20 =      

    5b = -20

    Now divide each side by 5

    5b             -20

    ___    =   _____

    5                  5

    b = -4

    The rest follow the same concept as problem 1

    2.  -4x + 3(2x-5)

    -4x + (3)(2x) - (3)(5) =

    -4x +6x - 15

    Now combine the like terms (x)

    2x -15 =

    2x = 15

    x = 15 / 2

    3.  2(3a+2) =

         6a+4

         6a = -4

         a = -4 / 6

    4.  -4 + 2(3+d)

         -4 + 6+2d

        2 + 2d

        2d = -2

        d = -2 / 2

        d = -1


  2. I'll give it a try:

    a. -w+4(w+3)...distribute

    -w^2-3w+4w+12... add the numbers and coefficient of the same kind

    = -w^2+w+12... ur answer

    b. 5(b+4)-6b... distribute

    5b+20-6b... add the same kind

    = -b+20... ur answer

    c. -4x+3(2x-5)

    -8x^2+20x+6x-15

    = -8x^2+26x-15

    ...the only thing that I am not sure is if you have to find the value of the coefficient, then that'll be different...

    eg.

    d. 2(3a+2)... if you just distribute, then

    6a+4... will be the final answer but it can go as far as this

    6a=-4... put "4" on the other side of the equal... before it was

    6a+4=0... but now it's

    6a=(-4)... then cancellation meaning in able to just retain the "a" you have to divide "6" on both side

    6a/6=(-4)/6... so

    a= -4/6 or a= -2/3

    I amtrying to help... i hope i didn't add to your confusion...

    =)


  3. The key parts to these problems is knowing distribution rules.

    a(b+c) is equal to ab + ac

    For your first problem.....

    5(b+4) - 6b

    1) You must first distribute (multiply) the five into the b + 4

    5(b+4) - 6b = 5b +20 -6b

    2) You now combine like terms

    5b - 6b + 20 = -1b +20

    -1b + 20 is your final answer.

    For Problem Number Two same story.....

    -4x + 3(2x-5)

    1) Distribute the three into both terms (2x-5)

    -4x + 3(2x-5) equals becomes -4x + 6x - 15

    2) Combine Like Terms

    -4x + 6x - 15 becomes 2x -15

    2x-15 is the final answer


  4. every time there is a number next to a parenthesis like a(b+c), you have to distribute the number to all terms within the parenthesis

    so in that case, you would do

    a*b + a*c, which gives you ab+ac

    Here are the solutions to your problems:

    -w+4(w+3)

    -w+4*w+4*3

    -w+4w+12

    3w+12

    same concept with the others

    5(b+4)-6b

    5*b+5*4-6b

    5b+20-6b

    -b+20

    -4x+3(2x-5)

    -4x+3*2x+3*-5 (DON'T forget the negative on the -5)

    -4x+6x-15

    2x-15

    2(3a+2)

    2*3a+2*2

    6a+4 (this one was pretty simple)

    -4+2(3+d)

    -4+2*3+2*d

    -4+6+2d

    2+2d

    Good luck!

    Tell your daughter to take her time and follow the order of operations!

  5. -w+4(w+3)=0

    (-w(w)+3w)+(4w+12)=0

    -w^2+7w+12=0 ; just multiply each variable with the other variable then

                               combine like terms

    5(b+4)-6b=0

    5b+(4*5)-6b=0

    5b+20-6b=0

    -b+20=0

    b=20

    -4x+3(2x-5)=0

    -4x+6x-15=0

    2x-15=0

    2x=15

    x=15/2

    2(3a+2)=0

    6a+4=0

    6a=-4

    a=-2/3

    -4+2(3+d)=0

    -4+6+2d=0

    2+2d=0

    2d=-2

    d=-1

  6. Here is an important thing: consider each number/letter a different expression, and the sign goes with the number/letter to the right of it (for example, -w and +4). Also whenever you multiply a number by a letter you just put the number and the letter together. Example: 3 times x =3x. And after you do the hard part, you have to simplify the equation at the end by adding together number/letter combinations that have the same endings only. Example: -13x+6x=-7x.

    1) u multiply each "expression" by each expression in the parentheses. So u multiply -w by w, -w*3, 4*w, and 4*3 to get -w squared -3w plus 4w + 12, and that simplifies to:

    -w squared +w + 12 (because -3w + 4w=1w or just w)

    2) in this case for know ignore the -6b and concentrate on the rule i stated above, so multiply 5*b to get 5b and 5*4 to get 20 to get 5b+20. then tack on the -6b at the end, and sense both 5b and -6b have common endings (b), you can put them together by adding to get:

    -b+20

    3) Use the rule. do -4x by 2x to get -8x squared (because a number/letter times itself is considered the number squared), -4x by -5 to get +20x (because a negative times a negative is always a positive), 3*2x to get +6x, and 3 by -5 to get -15. Simplify to get:

    -8x squared +26x -15

    4) The rule again, 2*3a is 6a, and 2*2 is 4 so the answer is:

    6a+4

    5) More rule (kind of repetitive but that's algebra). -4*3 to get -12, -4 by d to get -4d, 2*3 to get 6, and 2 by d to get 2d, and that simplifies to:

    -6-2d

    I hope that helped!!

    (By the way I am only 14 and I'm gonna b a freshman in high school)

  7. -w + 4 (w + 3)

    -w + 4w + 12

    3w + 12

    5 (b + 4) - 6b

    5b + 20 - 6b

    -b + 20

    -4x + 3 (2x - 5)

    -4x + 6x - 15

    2x - 15

    ask if you need more help in figuring it out : )

  8. i believe you just distribute. the 1st would turn into 5b+20-6b then you would simplify that even more to -b+20.

    the 3rd would be 6a+4. you just multiply the number on the outside by the numbers on the inside.

    i hope i helped haha :]

  9. -w+4(w+3).  Distribute the 4 across the parens.

    -w+4w+12.  Add up the like variables (-1w and +4w).

    3w+12.  Done.

  10. 1. -w + 4(w + 3)

    first, use the distributive property and multiply each of the terms in parentheses by 4.

    -w + 4w + 12

    now combine like terms.

    3w + 12

    if you wanted to get really technical, you could now factor out the greatest common factor (3 in this case).

    3(w + 4)

    2.  5(b + 4) - 6b

    once again, distribute the five to each of the enclosed terms.

    5b + 20 - 6b

    and combine like terms again.

    20 - b

    3. -4x + 3(2x -5)

    where to go from here?  you guessed it, distributive property!  : )

    combine like terms to finish off.

    -4x + 6x -15  -->  2x - 15

    4.  2(3a + 2)

    i think you know what to do...

    6a + 4

    5.  -4 + 2(3 + d)

    now distribute, combine like terms, and undistribute (gcf).

    -4 + 6 + 2d  -->  2d + 2  -->  2(d + 1)

    hope this completely refreshed your memory!  : )

  11. ok...

    1st multiply  -w*w = -w squared

    2nd multiply  -w*3 = -3w

    3rd multiply  4*w = 4w

    4th mutiply  4*3 = 12

    answer -w2-3w+4w+12

    simplified -w2 + w +12

    (the -w2 is negative w squared)

    hope this helps!

  12. this is a method i learned last year

      multiply                                  -w+4(w+3)

    First terms                               -w+-3w+4w+12

    Outter terms                    

    Inner terms

    Last terms

    FOIL

    then add the like terms         -w+1w+12

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