\(4x^2.\left(7+3x\right)-\left(3x-7\right)\)
\(=28x^2+12x^3-\left(3x-7\right)\)
\(=28x^2+12x^3-3x+7.\)
Chúc bạn học tốt!
\(4x^2\left(7x+3x\right)-\left(3x-7\right)\)
\(=4x^2\left(7+3x\right)+\left(3x+7\right)\)
\(=\left(4x^2+1\right)\left(7+3x\right)\)
hk bt có đúng hơm nx