\(3\left(5-2x\right)-\left(2x+1\right)\left(3-5x\right)\)
\(=15-6x-\left(6x-10x+3-5x\right)\)
\(=15-6x-6x+10x-3+5x\)
\(=12+3x\)
3(5-2x)-(2x+1)(3-5x)
=15-6x+10x2-x-3
=10x2-7x+12
Mình nhầm để làm lại cho nha :
\(3\left(5-2x\right)-\left(2x+1\right)\left(3-5x\right)\)
\(=15-6x-\left(6x-10x^2+3-5x\right)\)
\(=15-6x-6x+10x^2-3+5x\)
\(=12-7x+10x^2\)