Question

Foil (ab - 9)(ab + 8)

Answer 1

Step 1: (ab-9)(ab+8)

Step 2: ab x ab +8 x ab -9 x ab -9 x 8

Step 3:  ab2  +8ab-9ab-72=

Step 4: ab2 -ab-72

solved!!! that how you would solve it everything will continue as normal

Answer 2

(ab)² + 8ab - 9ab - 72
a²b² - ab - 72