10(7g-9h)-4h-8(-h+8g)
solve for g
7g + 8g since both are positive
15g
solve for h
9h+4h since both are negative
-14h
10-8 since the 8 is negative
12
12(15g-14h)
Since you typed the same equation twice I didn’t know if you meant to , so if it was meant to be doubled it would be
4(30g-28h)