Question

a/ 3 + x = 7

b/ -3x + 5 = -22

c/ -3.|x-1| = -9

giải hộ mik 3 câu

ai nhanh mik tik mik cần gấp lmws

Answer 1

a, 3+x=7

=>x=4

b, -3x+5=-22

=>-3x=-27

=>x=9

c, -3./x-1/=-9

/x-1/=3

th1: x-1=3 th2: x-1=-3

=>x=4 =>x=-2

Answer 2

\(a,3+x=7\)

\(x=7-3\)

\(x=4\)

Vậy \(x=4.\)

\(b,-3x+5=-22\)

\(-3x=-22-5\)

\(-3x=-27\)

\(x=\left(-27\right)\div\left(-3\right)\)

\(x=9\)

Vậy \(x=9.\)

\(c,-3\left|x-1\right|=-9\)

\(\left|x-1\right|=\left(-9\right)\div\left(-3\right)\)

\(\left|x-1\right|=3\)

\(\Rightarrow\left[{}\begin{matrix}x-1=3\\x-1=-3\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=4\\x=-2\end{matrix}\right.\)

Vậy \(x\in\left\{4;-2\right\}\)

Answer 3

a) \(3+x=7\Leftrightarrow x=7-3=4\)

KL: Vậy x=4

b) \(-3x+5=-22\Leftrightarrow-3x=-22-5=-27\Leftrightarrow x=\frac{-27}{-3}=9\)

KL: Vậy ...................

c) \(-3\left|x-1\right|=-9\Leftrightarrow\left[{}\begin{matrix}-3\left(x-1\right)=-9\\-3\left(1-x\right)=-9\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1=\frac{-9}{-3}=3\\1-x=\frac{-9}{-3}=3\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-2\end{matrix}\right.\)

KL: Vậy................

Answer 4

a/ 3 + x = 7

\(\Leftrightarrow\) x = 7 - 3

\(\Leftrightarrow\) x = 4.

Vậy x = 4.

b/ -3x + 5 = -22

\(\Leftrightarrow\) -3x = (-22) - 5

\(\Leftrightarrow\) -3x = -27

\(\Leftrightarrow\) x = (-27) : (-3)

\(\Leftrightarrow\) x = 9.

Vậy x = 9.

c/ -3.|x-1| = -9

\(\Leftrightarrow\) | x-1| = (-9) : (-3)

\(\Leftrightarrow\) |x -1| = 3

\(\Rightarrow\) x - 1 = 3 hoặc x - 1 = -3

\(\Leftrightarrow\) x - 1 = 3 \(\Leftrightarrow\) x - 1 = -3

\(\Leftrightarrow\) x = 3 + 1 \(\Leftrightarrow\) x = (-3) + 1

\(\Leftrightarrow\) x = 4. \(\Leftrightarrow\) x = -2.

\(\Leftrightarrow\) \(\left[{}\begin{matrix}x=4\\x=-2\end{matrix}\right.\)

Vậy x = 4 hoặc x = -2.