1) x³-49x=0 2) 7x²=(2x+1)²+3x²-5 3) (x-2)³+(x+2)³=2x(x²-1)+3 4) x³-3x²+2x-6=0 5) x³+2x²-9x-18=0 6) 7-(2x-2)*(4x+1)=2x*(5-4x) 7) (5-x)²-(3x-2)*(2x+1)=x*(2-5x)

1) x³-49x=0 x(x²-49)=0 x(x-7)(x+7)=0 x₁=0 x-7=0 x₂=7 x+7=0 x₃=-7 2) 7x²=(2x+1)²+3x²-5 7x²=4x²+4x+1+3x²-5 7x²=7x²+4x-4 7x²+4x-4-7x²=0 4x-4=0 4x=4 x=4:4 x=1 3) (x-2)³+(x+2)³=2x(x²-1)+3 (x-2+x+2)((x-2)²-(x-2)(x+2)+(x+2)²)=2x³-2x+3 2x(x²-4x+4-x²+4+x²+4x+4)=2x³-2x+3 2x(x²+12)=2x³-2x+3 2x³+24x=2x³-2x+3 2x³+24x-2x³+2x=3 26x=3 x=26/3 4) x³-3x²+2x-6=0 x²(x-3)+2(x-3)=0 (x²+2)(x-3)=0 x=3 5) x³+2x²-9x-18=0 x²(x+2)-9(x+2)=0 (x²-9)(x+2)=0 (x-3)(x+3)(x+2)=0 x-3=0 x=3 x+3=0 x=-3 x+2=0 x=-2 6) 7-(2x-2)*(4x+1)=2x*(5-4x) 7-(6x²-8x+2x-2)=10x-8x² 7-(6x²-6x-2)=10x-8x² 7-6x²+6x+2=10x-8x² -6x²+6x+9+8x²-10x=0 2x²-4x+9=0 D=4*4-4*2*9=16-72=-56<0 корней нет 7) (5-x)²-(3x-2)*(2x+1)=x*(2-5x) (25-10х+х²)-(6х²-4x+3x-2)=2x-5x² 25-10x+x²-6x²+x+2=2x-5x² -5x²-9x+27=2x-5x² 2x+9x=27 11x=27 x=27/11