\(5\left(2x-1\right)^2+4\left(x-1\right)\left(x+3\right)-2\left(5-3x\right)^2\)
\(=5\left(4x^2-4x+1\right)+4\left(x^2+3x-x-3\right)-2\left(25-30x+9x^2\right)\)
\(=20x^2-20x+5+4x^2+8x-12-50+60x-18x^2\)
\(=6x^2+48x-57\)
Chúc bạn học tốt!!!
Ta có : 5.(2x - 1)2 6 + 4.(x - 1) .(x +3) - 2.(5 - 3x)2
= 5 . (4x2 -4x + 1 )+ (4x - 4) .( x + 3) - 2. (52 - 30x + 9x2)
= 20x2 - 20x + 5 + 4x2 + 8x - 12 + ( -50 + 60x -18x2)
= 6x2 + 48x - 57