a) \(x^2-10x+9=x^2-x-9x+9=x\left(x-1\right)-9\left(x-1\right)=\left(x-1\right)\left(x-9\right)\)
b)\(x^2-10x+21=x^2-3x-7x+21=x\left(x-3\right)-7\left(x-3\right)=\left(x-3\right)\left(x-7\right)\) c)\(x^2-2x-3=x^2+x-3x-3=x\left(x+1\right)-3\left(x+1\right)=\left(x+1\right)\left(x-3\right)\)d)\(x^2-10x+16=x^2-2x-8x+16=x\left(x-2\right)-8\left(x-2\right)=\left(x-2\right)\left(x-8\right)\)e)\(x^2-2x-8=x^2+2x-4x-8=x\left(x+2\right)-4\left(x+2\right)=\left(x+2\right)\left(x-4\right)\)f)\(x^2-2x-48=x^2+6x-8x-48=x\left(x+6\right)-8\left(x+6\right)=\left(x+6\right)\left(x-8\right)\)g)\(x^2-10x+24=x^2-4x-6x+24=x\left(x-4\right)-6\left(x-4\right)=\left(x-4\right)\left(x-6\right)\)i)mình nghĩ câu này bị sai nên mình k giải đc. Mình nghĩ đề là \(x^4+3x^2-4\)
j)\(x^2-2x-15=x^2-3x+5x-15=x\left(x-3\right)+5\left(x-3\right)=\left(x-3\right)\left(x+5\right)\)
chúc bạn học tốt........
a,x2 - 10x + 9 = x2 - x - 9x + 9 = x(x - 1) - 9(x - 1) = (x - 9)(x - 1)
b,x2 - 10x + 21 = x2 - 3x - 7x + 21 = x(x - 3) - 7(x - 3)
c,x2 - 2x - 3 = x2 + x - 3x - 3 = x(x + 1) - 3(x + 1) = (x - 3)(x + 1)
d,x2 - 10x + 16 = x2 - 2x -8x + 16= x(x - 2) - 8(x - 2) = (x - 8)(x - 2)
e,x2 - 2x - 8 = x2 + 2x - 4x - 8 = x(x + 2) - 4(x + 2) = (x - 4)(x + 2)
f,x2 - 2x - 48 = x2 - 8x + 6x - 48 = x(x - 8) + 6(x - 8) = (x + 6)(x - 8)
g,x2 - 10x + 24 = x2 - 4x - 6x + 24 = x(x - 4) - 6(x - 4) = (x - 6)(x - 4)
j,x2 - 2x - 15 = x2 + 3x - 5x -15 = x(x + 3) - 5(x + 3) = (x - 5)(x + 3)
