Question

(3x-10)²-(5x+3)²

Answer 1

\(\left(3x-10\right)^2-\left(5x+3\right)^2\)

\(=\left(3x-10-5x-3\right)\left(3x-10+5x+3\right)\)

\(=\left(-13-2x\right)\left(8x-7\right)\)

\(=-\left(2x+13\right)\left(8x-7\right)\)

Answer 2

cách khác nè!!!

\(\left(3x-10\right)^2-\left(5x+3\right)^2=9x^2-2.3x.10+10^2-\left(25x^2+2.5x.3+9\right)\)

\(=9x^2-60x+100-\left(25x^2+30x+9\right)\)

\(=9x^2-60x+100-25x^2-30x-9\)

\(=-16x^2-90x+91\)