Question

tính
a) (x-3)(x+3)-(x+1)^2
b) (4x-3)(4x+3)-16x^2
c)(x+4)(x^2-4x+16)-x^3
làm hết hộ

Answer 1

a) \(\left(x-3\right)\left(x+3\right)-\left(x+1\right)^2\) = \(x^2-9-\left(x^2+2x+1\right)\)

\(x^2-9-x^2-2x-1\) = \(-2x-10\)

b) \(\left(4x-3\right)\left(4x+3\right)-16x^2\) = \(16x^2-9-16x^2=-9\)

c) \(\left(x+4\right)\left(x^2-4x+16\right)-x^3\) = \(x^3-4x^2+16x+4x^2-16x+64-x^3\)

= \(64\)

Answer 2

\(a,\left(x-3\right)\left(x+3\right)-\left(x+1\right)^2=x^2-9-x^2-2x-1=-10-2x\) \(b,\left(4x-3\right)\left(4x+3\right)-16x^2=16x^2-9-16x^2=-9\)\(c,\left(x+4\right)\left(x^2-4x+16\right)-x^3=x^3+64-x^3=64\)