\(\left(3x+2\right)^2-\left(3x-2\right)^2=5x+38\)
\(\Leftrightarrow9x^2+12x+4-9x^2+12x-4=5x+38\)
\(\Leftrightarrow24x-5x-38=0\)
\(\Leftrightarrow19x-38=0\)
\(\Leftrightarrow19\left(x-2\right)=0\)
\(\Leftrightarrow x-2=0\)
\(\Leftrightarrow x=2\)
VẬY ..
Đáp án:
\(S=\left\{2\right\}\)
Lời giải:
a) \(\left(3x+2\right)^2-\left(3x-2\right)^2=5x+38\)
\(\Leftrightarrow\left[\left(3x+2\right)-\left(3x-2\right)\right].\left(3x+2+3x-2\right)=5x+38\)
\(\Leftrightarrow\left(3x+2-3x+2\right).6x=5x+38\)
\(\Leftrightarrow24x=5x+38\)
\(\Leftrightarrow24x-5x=38\)
\(\Leftrightarrow19x=38\)
\(\Leftrightarrow x=2\)
Vậy phương trình có tập nghiệm là \(S=\left\{2\right\}\)
