Question

Simplifique em seu caderno as expressões : a) 3a (a - b) - 2a (a +b)
b) 2x (x-3) +x (x-5)
c) (x-3) . (x-5) + 3x (x +4 )
d) (a + b ) . (a-b) + (a- 2b) . (a + 5b )

Answer 1

A)3A(A-B)-2A(A+B)
 
 3A²-3AB-2A²-2AB = 1A² - 5AB

B)2X(X-3)+X(X-5)
 2X²-6X+X²-5X
 3X²-11X

C(X-3).(X-5)+3X(X+4)
 X²-5X-3X-15+3X²+12X
 4X²+4X-15

D)(A+B).(A-B)+(A-2B).(A+5B)
  A²-AB+AB-B²+A²+5AB-2AB
  2A²-B²+3AB

Answer 2

a) 3a(a-b)
3a² - 3ab - 2a² - 2ab
3a² - 2a² - 3ab - 2ab
a² - 5ab

b) 2x(x-3) +x (x-5)
2x² - 6x +x² -5x
2x² +x²-6x-5x
3x²-11x

c) (x-3)(x-5)+3(x+4)
3x-5x-9+15+3x+12
3x-5x+3x-9+15+12
6x-5x-9+27
x+18

d) (a+b)(a-b)+(a-2b)(a+5b)
a²-ab+ab-b²+a²+5ab-2ab-10b²
a²+a²+3ab-b²-10b²
2a²+3ab-11b²