Question

a) (-3)²-4-x²+5.x² b) (5.a.b).(-a)+(-4a).(3.a.b)

Answer 1

A)
= (-3)² - 4 - x² + 5.x²
= 9 - 4 - x² + 5x²
= 5 + 4x²
= 4x² + 5

***************************************
b)

= (5.a.b).(- a) + (- 4a).(3.a.b)

= - 5a²b - 12a²b

= - 17a²b