Question

Find AC
AB = -x + 25
BC = 3(2x - 8)

Answer 1

AC = 36

Explanation:

We could totally prove that AB ~= BC

But they didn't really ask for the proof, so we'll just use that idea.

-x + 25 = 3(2x - 8)

Use distributive property.

-x + 25 = 6x - 24

Add x to both sides.

25 = 7x - 24

Add 24 to both sides.

49 = 7x

Divide by 7

7 = x

Now we can calculate either AB or BC and double it(or calculate both AB and BC and add them together)

-x + 25

= -7 + 25

= 18

Both AB and BC are 18 so AC = 36

Calculating BC separately is also a good check.

3(2x - 8)

= 3(2•7 - 8)

= 3(14 - 8)

= 3(6)

= 18

So we get 2(18) or 18+18 to find that AC = 36