Question

If DF=78, DE=5x-9, and EF=2x+10 Find EF

Answer 1

EF = 32

Explanation:

DE + EF = DF

5x - 9 + 2x + 10 = 78

5x + 2x + 10 - 9= 78

7x + 1 = 78

7x = 78 - 1

7x = 77

x = 77/7

x = 11

`EF=2x+10 = 2 * 11 + 10 \\ EF=22 + 10 \\ \huge \red { \boxed{EF=32}}`