Đáp án:
a, `x=-\frac{7}{2}`
b, `x=5`
c. `x=5`
d, `x∈{5;-11}`
f, `x∈{5,75;-4,25}`
Giải thích các bước giải:
a, `\frac{-4}{7}x+\frac{1}{3}=\frac{7}{3}`
`⇔\frac{-4}{7}x=2`
`⇔x=\frac{-7}{2}`
Vậy: `x=\frac{-7}{2}`
b, `2\frac{1}{4}-25%x=1`
`⇔\frac{9}{4}-\frac{1}{4}x=1`
`⇔\frac{1}{4}x=\frac{5}{4}`
`⇔x=5`
Vậy: `x=5`
c, `5,5-\frac{1}{3}(x+1)=3\frac{1}{2}`
`⇔5,5-\frac{1}{3}x-\frac{1}{3}=\frac{7}{2}`
`⇔\frac{-1}{3}x=\frac{-5}{3}`
`⇔x=5`
Vậy: `x=5`
d, `\frac{x+3}{-8}=\frac{-8}{x+3}`
`⇔(x+3)^2=64`
`⇔`\(\left[ \begin{array}{l}x+3=8\\x+3=-8\end{array} \right.\)
`⇔`\(\left[ \begin{array}{l}x=5\\x=-11\end{array} \right.\)
Vậy: `x∈{5;-11}`
f, `\frac{9}{2}-|x-0,75|=\frac{-1}{2}`
`⇔|x-0,75|=5`
`⇔`\(\left[ \begin{array}{l}x-0,75=5\\x-0,75=-5\end{array} \right.\)
`⇔`\(\left[ \begin{array}{l}x=5,75\\x=-4,25\end{array} \right.\)
Vậy: `x∈{5,75;-4,25}`
