Question

How do I do #12?

Please show all work.

Please help!

Answer 1

You have the ratio set up correctly:

2x+2/12 = x+3/21

Now cross multiply:

2x+2 * 12 = x+3 * 21

Simplify:

24x + 24 = 21x + 63

Subtract 24 from each side:

24x = 21x + 39

Subtract 21x from each side:

3x = 39

Divide both sides by 3:

x = 39/3

x = 13