Question

A) -7x(x+2)+4 = -3x

b) -4(½x-2)-4= 2(-x+2)

c) 2-(x-2)²+3(x-7) =2-(x+1)(x-1)

d) x-2/3 -2x+1/4 + x/6 = -½

Answer 1

A) -7x(x+2)+4 = -3x
-7x²-14x+4+3x=0
-7x²-11x+4=0
delta=121-112=9
pierwiastek z delty=3
x1=(3+11)/14=1
x2=(-3+11)/14=4/7

b) -4(½x-2)-4= 2(-x+2)
-2x+8-4=-2x+4
4=4
zbiór pusty

c) 2-(x-2)²+3(x-7) =2-(x+1)(x-1)
2-(x²-4x+4)+3x-21=2-x²+1
2-x²+4x-4+3x-21-2+x²-1=0
7x=-26/7
x=-25/7


d) x-2/3 -2x+1/4 + x/6 = -½ pomnóż przez 6
-6x-2-6/4+x+3=0
5x=2/3
x=2/15