Math questions. :) please explain so i get it. :)?

Question

Write an inequality for each question.

1. Everyone in the class is under 13 yrs. old. Let x be the age of a person in a class.

2. The speed limit is 60 miles per hour. Let s be the speed of a car driving within the limit.

3. You have $4.50 to spend on lunch. Let c be the cost of your lunch.

Solve each equation.

1. 9y-11=7

2. m/4+6=3

3. -5b - 6= -11

4. v/-7+8=9

5. 15w - 21= -111

6. 7-2n = n-14

7. 3d+8=2d-7

8. 7x-8=3x+12

9. 6k-25=7-2k

Write an equation for the given line through the given points or through the given point with given slope.

1. (5,7),(6,8)

2. (-2,3); slope=1

3. (1,2),(3,8)

4. (-2,3);slope= 4

5. (4,7); slope=2/3

6. (6,-2); slope= -4/3

7. (0,5),(-3,2)

8. (8,11),(6,16)

Thanks. :)

Answer 1

X<13

s<60

c<4.50

1.y=2   (+ 11 on both sides you get 9y = 18, divide by 9 on both sides you get 2)

2.m=-12

3.b=1

4.v=1

do the rest your self

equation is y=mx+b

m = slope

slope = y of 2 divided by y of 1

the plug in the value of the slope and find b

b= y intercept

1. Y=x+2

2. y=x+5

3. y=3x-1

again do the rest your self else you will never learn

Answer 2

I'll do three....

1.)  x<13

2.) s<=60 mph

3.) c<=4.5

Solve each equation:

Tip: Get letters on one side and numbers on other side....

1.) 9y-11=7

add 11 to each side

9y-11+11=7+11

9y = 18  divide by 9 each side

y=2

2.)m/4+6=3

add -6

m/4=-3

Mult 4

m=-12

3.) -5b-6 = -11

Add 6

-5b=-5

Divide by -5

b=1

etc

Write an line equation of the form y=mx+b

Remember slope is m = (y2-y1)/(x2-x1)

with (x1,y1) and (x2,y2) being points on the line

knowing two points get the slope. Then take one point and slope to determine the equation.

1.) m=(8-7)/(6-5) = 2/1 = 2

equation becomes 2 = (8-y)/(6-x)

solve;            2(6-x) = (8-y)

                  

12-2x=8-y

-y=12-2x-8

-y = 4-2x

y=2x-4

2.) m=1, (x,y)= (-2,3)

1 =(y-3)/(x-(-2)) = (y-3)/(x+2)

x+2 = y-3

or y = x+5 answer

3.) m=(8-2)/(3-1) = 6/2 = 3

you can use either point to get the final equation:

   3 = (8-y)/(3-x)

   3(3-x) = 8-y

   9-3x=8-y

-y=9-8-3x

-y=1-3x

y=-1+3x = 3x-1

y=3x-1

done

Use the same techniques for the rest of the problems....

  

Answer 3

1. since 13 is the mximum age the bigger part of the sybol has gotta be facing the number, so it would look like x<13

2. same as one

3.same

1.9y-7=11

a good tipis getting like terms together

like numbers on one side and variables on the other

so you would add 7 to both sides to the problem would be

9y=18

divide by two

y=2

the rest are the same except that for some you need to get rid of fractions

ex. 1/2x=2

so what you do is multiply bothe sides by the fractions denominator

in this case two

it cancels the fractions

so it turns into x=4

as for slope[[i had trouble with this too]]

the main equation is y=mx+b

thats all i can tell you about that one