Question

calcule
a) (5x-1).(5x+1)
b) (a+b).(a+b)
c) (2x²-3x-6).(5x-2)

Answer 1

a) (5x - 1) . (5x + 1)

(5x)² - 1²

25x² - 1

b) (a+b).(a+b)

(a + b)¹ . (a + b)¹

(a + b) (soma os expoentes 1+1=2)

(a + b)²

c) (2x²-3x-6).(5x-2)

2x² .(5x - 2) - 3x . (5x - 2) - 6(5x - 2)

10x³ - 4x² - 15x² + 6x - 30x + 12

10x³ - 19x² - 24x + 12