## Answer :

4*2a+4*2-17=15

8a+8=15+17

8a+15+17-8

8a=24

a=3

16. -4x+3(2x-5)= 31

-4x+3*2x-3*5=31

-4x+6x-15=31

2x=31+15

2x=46

x=23

17. -6-3(2k+4)= 18

-6-3*2k-3*4=18

-6-6k-12=18

-18-6k=18

-6k=32

k=-32/6=-16/3

22. 2x+ 3/4(4x+16)=7

2x+(3/4)*4x++(3/4)*16=7

2x+3x+12=7

5x=-5

x=-1