b) F = (x² + 1)(x²-1)
6: Tìm x biết
a)
(x-2)²-(x-3)(x+3)=6
c) (x+4)²+(1-x)(1+x) = 7
e) 4(x-3)²-(2x-1)(2x+1)=10
g) 9(x+1)-(3x-2)(3x+2) = 10
c) G= (a + b)²+(a - b)²
b)
(x+3)+(4+x)(4-x)=10
d) (x-4)²-(x-2)(x+2) = 6
f) 25(x+3)+(1-5x)(1+5x) = 8
h) -4(x-1)²+(2x-1)(2x+1)=-3
2