Question

1. Tìm x, biết

a) 3| 2x + 5| -4= 1

b) 7- 2|1 -3x|= -5

c) |3x- 2| - |\(^{2^2}\)-3|= 4

Answer 1

a) 3| 2x + 5| -4= 1

=>3|2x+5|=5

\(\Rightarrow\left|2x+5\right|=\frac{5}{3}\)

\(\Rightarrow2x+5=-\frac{5}{3}\) hoặc \(\frac{5}{3}\)

Xét \(2x+5=-\frac{5}{3}\) 

\(\Rightarrow2x=\frac{20}{3}\Leftrightarrow x=-\frac{10}{3}\)

Xét \(2x+5=\frac{5}{3}\)

\(\Rightarrow2x=-\frac{10}{3}\)

\(\Rightarrow x=-\frac{5}{3}\)

 

Answer 2

b) 7- 2|1 -3x|= -5

=>2|1-3x|=12

=>|1-3x|=6

=>1-3x=6 hoặc -6

Xét 1-3x=6

=>3x=7 <=>\(x=\frac{7}{3}\)

Xét 1-3x=-6

=>3x=-5 <=>\(x=-\frac{5}{3}\)