Question

cho F(x)=x3+4x2-3x+2

G(x)=x2.(x+4)+x-5

tìm x để F(x) =G(x)

Answer 1

Fx)=G(x)  <=> x³+4x²-3x+2=x²(x+4)+x-5

<=> x³+4x²-3x+2=x³+4x²+x-5

<=> 4x=7  => x=7/4

Đáp số: x=7/4

Answer 2

           \(F\left(x\right)=G\left(x\right)\)

\(\Leftrightarrow\)\(x^3+4x^2-3x+2=x^2\left(x+4\right)+x-5\)

\(\Leftrightarrow\)\(x^3+4x^2-3x+2=x^3+4x^2+x-5\)

\(\Leftrightarrow\)\(-4x=-7\)

\(\Leftrightarrow\)\(x=\frac{7}{4}\)

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