Can someone help me with these algebra equations?

Question

i know you must be saying they're easy, but it's just been a while since i did em and i cant remember how to do them... these are the equations:

1.) x+2 all divided by 3 = 8/15

2.) 18/x = 6

3.) 5/7 = 10/x+2

please explain in steps how you got to the answer. thanks in advance to those who helps!

Answer 1

Just remember that whenever you're doing this sort of algebra question, the 1st thing you need to do is to try removing the fractions (that's what my maths teacher says :-D)

1) (x+2)/3 = 8/15

To remove the fractions you'll have to find the LCM (lowest common multiple) for all the denominators, in this case it's 15:

5(x+2)/3*5 = 8/15

(5x+10)/15 = 8/15

Now you got the same denominators, you can simply remove them to get some nice whole numbers:

5x+10 = 8

5x = -2

x = -2/5

2) 18/x = 6

(18*x)/x = 6*x

18 = 6x

x = 3

3) 5/7 = 10/x+2

[5(x+2)]/[7(x+2)] = [10(7)]/[7(x+2)]

5x+10 = 70

5x = 60

x = 12

Answer 2

one way to start is to get rid of the fractions

for #1, multiply both sides by 15

#2, multiply both sides by x

#3, multiply both sides by 7(x+2)

Answer 3

1)

(x + 2)/3 = 8/15

x + 2 = 3(8/15)

x + 2 = 8/5

x = 8/5 - 2

5x = 5(8/5 - 2)

5x = 8 - 10

x = -2/5 (-0.4)

2)

18/x = 6

18 = 6(x)

6x = 18

x = 18/6

x = 3

3)

5/7 = 10/(x + 2)

5(x + 2)/7 = 10

5*x + 5*2 = 7(10)

5x + 10 = 70

5x = 70 - 10

5x = 60

x = 60/5

x = 12

  

Answer 4

1) (x + 2)/ 3 = 8 /15

  (x + 2)..... = 8 * 3 / 15 -----( 3 goes in right side so that we multiply)

  x + 2  ......= 8 / 5 ( 3 divide by 15 = 5)

  x..............= 8/5 - 2 ...... (2 goes in right side and we sub)

  x..............= -2/ 5 .........( you calculate by using factorization or LCM method)

2) 18/ x = 6

    6x = 18 ( x goes in another direction so we multiply)

    x = 18/ 6 ( 6 goes in another direction so we divide)

   x = 3  ( 18 divide by 6 = 3)

3) 5/7 = 10/x + 2

5/7 - 2 = 10/x

-9 /7 .....= 10/x    ( you factorise )

- 9x/7 .....= 10 (x goes in another direction)

- 9x ........= 10*7

x ...........= -70 / 9

i hope it helps you to understand or remember them now!! :)