Question

1)7x^3-14x^2-x+2=0
2)(x^2-8)^2-3(x^2-10)-4=0​

Answer 1

1. 7x³-14x²-x+2=0;
7x²×(x-2)-(x-2)=0;
(x-2)×(7x²-1)=0;
x-2=0;
7x²-1=0;
x=2;
x1= - √7/7;
x2= √7/7.

2. (x²-8)²-3(x²-10)-4=0;
x⁴-16x²+64-3x²+30-4=0;
x⁴-19x²+90=0;
t²-19t+90=0;
t=9;
t=10;
x²=9;
x²=10;
x1=-3;
x2=3;
x3=-√10;
x4=√10.