## anonymous one year ago find the value of y

1. anonymous

2. freckles

those are length measurements right?

3. freckles

if so you might want to solve for x first then use similar triangles to find y

4. anonymous

Okay, but i dont know how to

5. freckles

we are given that 5x+8 is equal to 21x

6. freckles

can you solve for x now?

7. freckles

I'm asking if you know how to solve 5x+8=21x for x?

8. anonymous

Subtract 8 from both sides?

9. freckles

8 has no friends on the other side why not trying to subtract 5x on both sides

10. anonymous

i got you,okay so x=8

11. freckles

wait did you subtract 5x on both sides? 8=21x-5x 8=16x now divide both sides by 16

12. anonymous

2?

13. freckles

8/16 shouldn't be 2 but 1/2

14. freckles

these are two difference numbers

15. anonymous

okay so i got 0.5

16. freckles

anyways x=1/2 which means if x=1/2 then 21x is 21/2 or if you plugged x into the other expression 5x+8 you should still get 21/2 moving the bar up to show the similar triangles in a more obvious way: |dw:1438743769937:dw|

17. freckles

now set up your equivalent ratios and solve for y

18. freckles

|dw:1438743912912:dw| $\frac{a}{c}=\frac{a+b}{c+d}$