Question

Giúp em với mọi người ơi

Answer 1

\(1.2x^2-x-2x^2-5=0\)

\(-x-5=0\Leftrightarrow x=-5\)

\(2.-2x^2-x+2x^2-2=0\)

\(-x-2=0\Leftrightarrow x=-2\)

\(3.12x^2+3x+24x-12x^2=0\)

\(27x=0\Leftrightarrow x=0\)

\(4.-5x^2+5x+5x^2+5x=0\)

\(10x=0\Leftrightarrow x=0\)

\(5.-7x^2-\dfrac{7}{3}x-x+7x^2=0\)

\(\dfrac{-10}{3}x=0\Leftrightarrow x=0\)

\(6.-20x+10x^2-5x^2-10x-5x^2-15x=0\)

\(-45x=0\)

\(x=0\)

Answer 2

$1.2{}^{}-x-2{}^{}-5=0$

$-x-5=0\iff x=-5$

$2.-2{}^{}-x+2{}^{}-2=0$

$-x-2=0\iff x=-2$

$3.12{}^{}+3x+24x-12{}^{}=0$

$27x=0\iff x=0$

$4.-5{}^{}+5x+5{}^{}+5x=0$

$10x=0\iff x$