(x+2).(x-2) - (x-3).(x+1)
= x2 - 4 - x2 - x + 3x + 3
= (x2 - x2) + (3x - x) + (3-4)
= 2x - 1
\(\left(x+2\right)\left(x-2\right)-\left(x-3\right)\left(x+1\right)\)
\(=\left(x^2-2x+2x-4\right)-\left(x^2+x-3x-3\right)\)
\(=x^2-2x+2x-4-x^2-x+3x+3\)
\(=x^2-x^2-2x+2x+3x-4+3\)
\(=3x-1\)
Chúc bạn học tốt!!!
\(\left(x+2\right)\left(x-2\right)-\left(x-3\right)\left(x+1\right)\)
\(=x^2-4-\left(x^2+x-3x-3\right)\)
\(=x^2-4-x^2-x+3x+3\)
\(=2x-1\).
vo van ve dau tien rut gon thanh hang dang thuc xong roi ve kia nhan het vao