Question

a) (-15) . x = -120

b) x . (-5) = 15

c) 140 : x = -20

d) x^2 = 25

e) 20 - 4x = 28 

g) -3 x^2 = -12

mik cần gấp nha

Answer 1

\(a,\Rightarrow x=\dfrac{-120}{-15}=8\\ b,\Rightarrow x=\dfrac{15}{-5}=-3\\ c,\Rightarrow x=\dfrac{140}{-20}=-7\\ d,\Rightarrow x^2=5^2=\left(-5\right)^2\Rightarrow\left[{}\begin{matrix}x=5\\x=-5\end{matrix}\right.\\ e,\Rightarrow4x=-8\Rightarrow x=-2\\ g,\Rightarrow x^2=\dfrac{-12}{-3}=4\Rightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\)