Răspuns:
Explicație pas cu pas:
a) (x-1)(x-2) = x(x-2)-1(x-2) = x²-2x-x+2 = x²-3x+2
b) (x-3)(x+6) = x(x+6)-3(x+6) = x²+6x-3x-18 = x²+3x-18
c) (x+4)(x+5)=x(x+5)+4(x+5) = x²+5x+4x+20= x²+9x+20
d) (2x+7)(x-2)=2x(x-2)+7(x-2)=2x²-4x+7x-14= 2x²+3x-14
e) (1-2x)(3x+5)=1(3x+5)-2x(3x+5) = 3x+5-6x²-10x= -6x²-7x+5
f) (2x+3)(5x-4)=2x(5x-4)+3(5x-4) = 10x²-8x+15x-12=10x²+7x-12
g) (2a+3b)(3a-b)=2a(3a-b)+3b(3a-b) = 6a²-2ab+9ab-3b²=6a²+ab-3b²
h) (4x-3)(4x+3)=4x(4x+3)-3(4x+3) = 16x²+12x-12x-9=16x²-9
i) (4x-5y)(3x+3y)=4x(3x+3y)-5y(3x+3y)=12x²+12xy-15xy-15y²=12x²-3xy-15y²
