Question

Viết tổng sau thành tích

a) x² - 4x + 1

b) x² - 2xy + y²

c) x² + 2xy + y²

d) x² - 1

e) x² + 3x +2

f) x² - 7x + 12

Answer 1

\(e,x^2+3x+2=x^2+2x+x+2=x.\left(x+2\right)+x+2=\left(x+1\right).\left(x+2\right)\)

\(f,x^2-7x+12=x^2-3x-4x+12=x.\left(x-3\right)-4.\left(x-3\right)=\left(x-4\right).\left(x-3\right)\)

\(d,x^2-1=x^2-x+x-1=x.\left(x-1\right)+\left(x-1\right)=\left(x+1\right).\left(x-1\right)\)

\(c,x^2+2xy+y^2=x^2+xy+xy+y^2=x.\left(x+y\right)+y.\left(x+y\right)=\left(x+y\right)^2\)

\(b,x^2-2xy+y^2=x^2-xy-xy+y^2=x.\left(x-y\right)-y.\left(x-y\right)=\left(x-y\right)^2\)

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