a) (x-9)(x-5)=x²+56-14x b) x²-(x+3)(x+4)=x+20 c) (x-1)(x+1)-x(x+2)-1=2(x+1) d) 4(x+2)²=(2x+1)(2x+1)-2(2x-1)

a) (x-9)(x-5)=x²+56-14x xdo kwadratu-5x-9x+45=xdo kwadratu+56-14x -14x+45=56-14x 0x=11 b) x²-(x+3)(x+4)=x+20 xdo kwadrau-[xdo kwadratu+4x+3x+12]=x+20 xdo kwadratu-xdo kwadratu-4x-3x-12=x+20 -7x-12=x+20 -6x=32/:(-6) x=5i1/3 c) (x-1)(x+1)-x(x+2)-1=2(x+1) xdo kwadratu-1-xdo kwadratu-2x-1=2x+2 -2x-2=2x+2 -4x=4/:(-4) x=-1 d) 4(x+2)²=(2x+1)(2x+1)-2(2x-1) 4[xdo kwadratu+4x+4]=4xdo kwadratu+1-4x+2 4xdo kwadratu+16x+16=4xdo kwadratu+3-4x 16x+16=3-4x 20x=-13/20 x=-13/20 sorrki ze bez indeksu górnego w potegach....

a) (x-9) (x-5) = x² + 56-14x x²-5x-9x+45= x²+56-14x x²-5x-9x-x²+14x= 56-45 0=11 b) x²- (x+3)(x+4) = x+20 x²-x²-4x-3x-12=x+20 x²-x²-4x-3x-x= 20+12 -8x =32 / ÷ (-8) x=4 c) (x-1)(x+1)-x(x+2)-1=2(x+1) x²+x-x-1-x²-2x-1=2x+2 x²+x-x-x²-2x-2x=2+1+1 -4x=4 /÷ (-4) x=1 d) 4(x+2)²=(2x+1)(2x+1)-2(2x-1) 4(x²+4x+4)=4x²+1-4x+2 4x²+16x+16=4x²+1-4x+2 4x²+16-4x²+4x=1+2-16 20x= -13 /÷ 20 x= - 13/20