Question

Преобразовать в многочлен 

1). ( 5-b)(5+b)-2b (b-3)

2)  -5y(y+3)+(y-4)^2

3).  3(x-2)^2-3x^2

Answer 1

1) (5-b)(5+b)-2b(b-3) = [(5-b)(5+b) - разность квадратов] = 5²-b²-2bb-3*(-2)b = 25-b²-2b²+6b = -3b²+6b+25

2) -5y(y+3)+(y-4)² = -5уу+3*(-5)у+(у²-2*4у+4²) = -5у²-15у+у²-8у+14 = -4у²-23у+16

3) 3(x-2)²-3x² = 3(х²-2*2х+2²)-3х² = 3х²-12х+12-3х² = -12х+12