\(2a-\left(5-4a\right)+\left(6a-1\right)-\left(2+a\right)\)
\(5a-2b+3-\left(2a-5b+6\right)+\left(a+3b-1\right)\)
\(6x\left(x-1\right)-1\left(6x^2-8x+3\right)=7-\left(x-1\right)\)
\(7x\left(2x-1\right)-\left(14x^2-8x+5\right)=7-\left(-2x+3\right)\)
Thanks các bạn nhiều nha
2a - (5- 4a) +(6a -1) -(2+a)
= -10a - 8a^2 +6a -1 -2 -a
= -8a^2 -5a -3
5a - 2b +3 - (2a -5b +6) +(a+3b -1)
= 5a -2b +3 -2a+5b -6 +a + 3b -1
= 4a +6b -4
6x(x-1) -1(6x^2 -8x +3) = 7 -(x-1)
6x^2 -6x - 6x^2 + 8x -3 = 7 -x +1
3x = 11
x= 11/3
7x(2x-1) - (14x^2 -8x +5) = 7- (-2x +3)
14x^2 - 7x - 14x^2 + 8x - 5 = 7 + 2x -3
-x = 9
x=-9