Đáp án:
a, (2x-1)(x-5)-x(4+2x)=2x(x-5)-1(x-5)-4x-2x^2=2x^2-10x-x+5-4x-2x^2=-15x+5
b, (2x-3)^2-(2x-3)(2x+3)=(2x-3)(2x-3-2x-3)=-6(2x-3)
c, ___2x___+___10x____=___2x___+____10x___=___2x^2___+___10x___=__2x^2+10x__= ___2x(x+5)__ =2
x+5 x^2+5x x+5 x(x+5) x(x+5) x(x+5) x(x+5) x(x+5)
d, ____x____+___x-6___+____-36______=_____x_____+____x-6__+___-36____=___x^2______+___(x-6)^2____
x^2-36 x^2+6x (x^2-6x)(x+6) (x-6)(x+6) x(x+6) x(x-6)(x+6) x(x-6)(x+6) x(x-6)(x+6)
+____-36____=___x^2+(x-6)^2-36___=___2x(x-6)___=___2____
x(x-6)(x+6) x(x-6)(x+6) x(x-6)(x+6) x+6
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