Đáp án:
Giải thích các bước giải:
a, ___7___ + _____5-x _____= ____x-1_____+____1____
8x 4x^2-8x 2x(x-2) 8x-16
<=> ___7___ + ____5-x____ = ___x-1___ + ___1___
8x 4x(x-2) 2x(x-2) 8(x-2)
<=>__7.2x(x-2)__ + ___2(5-x)___=___4(x-1)+x___
8x(x-2) 8x(x-2) 8x(x-2)
<=>__14x^2 -28x_+_10-2x___=___4x-4+x___
8x(x-2) 8x(x-2)
=>14x^2 -28x +10 - 2x = 4x-4+x
<=> 14x^2 -30x+10= 5x-4
<=>14x^2 -35x+14=0