Question

1.oblicz ;

a). 3(x+1)(x-2)-3x²=

b). 2x²-(x-4)(x-5)=

c).1-(x-1/2)(x-4)=

d). 3(x+1)(4-2)(x-1)=

proszę o rozwiązanie ! ;)

Answer 1

a) 3x+3*(-2x)-3x²=3x+(-6x)-3x²=(-3x)-3x²
b) 2x²-(x-4)(x-5)=2x²-(-4x)(-5x)=2x²-20x
c) 1-(x-1/2)(x-4)=1-(-x+1/2)(-4x)=1-(-1/2x)(-4x)=1-4 1/2x
d) 3(x+1)(4-2)(x-1)=(3x+3)(2)(-1x)=3-2=-1x-3x=1*2x

Answer 2

a). 3(x+1)(x-2)-3x²=3(x²-2x+x-2)-3x²=3x²-6x+3x-6-3x²=-3x-6

b). 2x²-(x-4)(x-5)=2x²-(x²-5x-4x+20)=2x²-x²+5x+4x-20=x²+9x-20

c). 1-(x-1/2)(x-4)=1-(x²-4x-½x+2)=1-x²+4x+½x-2=4½x-x²-1

d). 3(x+1)(4-2)(x-1)=3(4x-2x+4-2)(x-1)=3(4x²-2x²+4x-2x-4x+2x-4+2)=

=12x²-6x²+12x-6x-12x+6x-12+6=6x²-6