Question

Giải phương trình

a) x ( x+2) = x ( x+3)

b) 2(x-3)+5x(x-1) = \(5x^2\)

Answer 1

a) \(x\left(x+2\right)=x\left(x+3\right)\)

\(\Leftrightarrow x^2+2x=x^2+3x\)

\(\Leftrightarrow3x-2x=0\)

\(\Leftrightarrow x=0\)

Vậy phương trình có nghiệm \(x=0.\)

b) \(2\left(x-3\right)+5x\left(x-1\right)=5x^2\)

\(\Leftrightarrow2x-6+5x^2-5x-5x^2=0\)

\(\Leftrightarrow-3x-6=0\)

\(\Leftrightarrow x=-2\)

Vậy phương trình có nghiệm \(x=-2.\)

Answer 2

a) Ta có: x(x+2)=x(x+3)

⇔\(x^2+2x=x^2+3x\)

\(\Leftrightarrow x^2+2x-x^2-3x=0\)

\(\Leftrightarrow-x=0\)

hay x=0

Vậy: x=0

b) Ta có: \(2\left(x-3\right)+5x\left(x-1\right)=5x^2\)
\(\Leftrightarrow2x-6+5x^2-5x-5x^2=0\)

\(\Leftrightarrow-3x-6=0\)

\(\Leftrightarrow-3x=6\)

hay x=-2

Vậy: x=-2

Answer 3

A. x(x+2)=x(x+3)

=>x+2=x+3

=>x-x=3-2

=>ptvn

B. 2(x-3)+5x(x-1)=5x²

=>2x-6-5x=0

=>-3x=6

=>x=-2