`@` `\text {Ans}`
`\downarrow`
`a)`
`-2x=5*6`
`=> -2x = 30`
`=> x=30 \div (-2)`
`=> x=-15`
Vậy, `x=-15`
`b)`
`x/(7,5) = 2022/(2,5)`
`=> 2,5x = 7,5*2022`
`=> 2,5x=15165`
`=> x=15165 \div 2,5`
`=> x=6066`
Vậy, `x=6066`
`c)`
`(x^2)/8 = 9/2`
`=> 2x^2 = 9*8`
`=> 2x^2 = 72`
`=> x^2 = 72 \div 2`
`=> x^2 = 36`
`=> x^2 = (+-6)^2`
`=> x=+-6`
Vậy, `x \in {6; -6}`
a) \(-2x=5\cdot6\)
\(\Rightarrow-2x=30\)
\(\Rightarrow x=\dfrac{30}{-2}=-15\)
b) \(\dfrac{x}{7,5}=\dfrac{2022}{2,5}\)
\(\Rightarrow x=\dfrac{7,5\cdot2022}{2,5}\)
\(\Rightarrow x=6066\)
c) \(\dfrac{x^2}{8}=\dfrac{9}{2}\)
\(\Rightarrow x^2=\dfrac{8\cdot9}{2}\)
\(\Rightarrow x^2=36\)
\(\Rightarrow x=\pm\sqrt{36}=\pm6\)
a
<=> -2x = 30
=> \(x=\dfrac{30}{-2}=-15\)
b
<=> \(x=\dfrac{2022}{2,5}.7,5=\dfrac{2022.2,5.3}{2,5}=2022.3=6066\)
c
<=> \(x^2=\dfrac{9}{2}.8=\dfrac{72}{2}=36\\ \Rightarrow x=\pm6\)
a) -2x = 5.6
-2x = 30
x = 30 : (-2)
x = -15
b) x/7,5 = 2022/2,5
x = 2022 . 7,5 : 2,5
x = 6066
c) x²/8 = 9/2
x² = 9.8/2
x² = 36
x = 6 hoặc x = -6