Question

Решите уравнение 1) (х+9)²-х(х+8)=1 2) (х-11)²=(х-7)(х-9) 3) (х-4)(х+4)-(х+6)²=-16 4) (1-3х)²-х(9х-2)=5

Answer 1

$(x+9)^2-x(x+8)=1 \\ x^2+18x+81-x^2-8x=1 \\ 10x+80=0 \\ 10x=-80 \\ x=-8 \\ \\(x-11)^2=(x-7)(x-9) \\x^2-22x+121=x^2-7x-9x+63 \\ -22x+16x=63-121 \\ -6x=-58 \\ x= \frac{58}{6}=9 \frac{4}{6}=9 \frac{2}{3} \\ \\(x-4)(x+4)-(x+6)^2=-16 \\ x^2-16-x^2-12x-36=-16 \\ -12x-36=0 \\ -12x=36 \\ x=-3 \\ \\ (1-3x)^2-x(9x-2)=5 \\ 1-6x+9x^2-9x^2+2x=5 \\ -4x=4 \\ x=-1$