Question

tìm x

a)(x-3)^2+x(10-x)=7

b)(x-2)^2-x(x-1)=13

Answer 1

\(a,\left(x-3\right)^2+x\left(10-x\right)=7\)

\(\Leftrightarrow x^2-6x+9+10x-x^2=7\)

\(\Leftrightarrow4x=-2\)

\(\Leftrightarrow x=-\dfrac{1}{2}\)

\(b,\left(x-2\right)^2-x\left(x-1\right)=13\)

\(\Leftrightarrow x^2-4x+4-x^2+x=13\)

\(\Leftrightarrow-3x=9\)

\(\Leftrightarrow x=-3\)

Answer 2

a) (x-3)^2+x(10-x)=7

<=> x² - 6x + 9 + 10x - x² = 7

<=> -6x + 10x = -2

<=> 4x = -2

<=> x = - 1/2

b)(x-2)^2-x(x-1)=13

<=> x² - 4x + 4 - x² -x = 13

<=> -5x = 9

<=> x = -9/5

P/s: mình làm đại thôi có sai sót bạn sửa nhé ^^