giúp mình với ạ:33
Thực hiện phép tính và rút gọn (nếu có thể)
1)(x+3)(x-1)-(x-7)(x-6)
2)(-x-2)(x+1)-(x-5) (-x+1)
3)5x(x-3)(x-1)-4x(x^2-2x)
4)-4x(x+3(x-4)-3x(x^2-x+1)
5) 4x(^2-x+3)-(x-6)(x-5)
giúp mình với ạ:33 Thực hiện phép tính và rút gọn (nếu có thể) 1)(x+3)(x-1)-(x-7)(x-6) 2)(-x-2)(x+1)-(x-5) (-x+1) 3)5x(x-3)(x-1)-4x(x^2-2x) 4)-4x(x+3(
By Vivian
1) (x+3)(x-1)-(x-7)(x-6)= (x²-x+3x-3)-(x²-6x-7x+42)
= x²+2x-3-x²+13x-42
= 15x-45
2) (-x-2)(x+1)-(x-5)(-x+1)= -x²-x-2x-2-(-x²+x+5x-5)
= -x²-3x-2+x²-6x+5
= -9x+3
3) 5x(x-3)(x-1)-4x(x^2-2x)= 5x(x²-x-3x+3)-4x³+8x²
= 5x³-20x²+15x-4x³+8x²
= x³-12x²+15x
4) -4x(x+3)(x-4)-3x(x^2-x+1)= -4x(x²-4x+3x-12)-3x³+3x²-3x
= -4x³+4x²+48x-3x³+3x²-3x
= -7x³+7x²+45x
5) 4x(x^2-x+3)-(x-6)(x-5)= 4x³-4x²+12x-x²+5x+6x-30
= 4x³-5x²+23x-30
1) (x+3)(x-1)-(x-7)(x-6)
<=> x2 –x+3x-3-(x2-6x-7x+42)
<=> x2-x+3x-3-x2+6x+7x-42
<=> 15x-45
<=> 15(x-3)
2) (-x-2)(x+1)-(x-5) (-x+1)
<=> (x+1) (-x-2-(x-5))
<=> (x+1) (-x-2-x+5)
<=> (x+1) (-2x+3)
3)5x(x-3)(x-1)-4x(x2-2x)
<=>5x(x-3)(x-1)-4x(x2-2x)
<=>5x (x2-x-3x+3)-4x3 + 8x2
<=>5x3– 5x2 -15x2 +15x -4x3+ 8x2
<=>x3-12x2+15x
<=>x(x2-12x+15)
4) -4x(x+3)(x-4)-3x(x^2-x+1)
<=>-4x(x+3)(x-4)-3x(x^2-x+1)
<=>-4x(x2-4x+3x-12)-3x3+4x2-3x
<=>-4x3+16x2-12x2+48x-3x3+4x2-3x
<=>-7x3+8x245x
5) 4x(x^2-x+3)-(x-6)(x-5)
<=>4x(x^2-x+3)-(x-6)(x-5)
<=>4x3-4x2+12x-(x2-5x-6x+30)
<=>4x3-4x2+12x-x2+5x+6x-30
<=>4x3-5x2+23x-30