\(5x-3^2-4x-7^2=0\)
\(5x-4x-3^2-7^2=0\)
\(5x-4x=3^2+7^2\)
\(x=9+49\)
\(x=58\)
a, 5x-32-4x-72=0
x-(32+72)=0
x-(9+49)=0
x-58=0
x=58
b, 5x-1.2x-1=3x+8x-1
5x-2x-3x-8x=-1+1
-8x=0
x=0
\(5x-1\cdot2x-1=3x+8\cdot x-1\)
\(5x-2x-1=3x+8x-1\)
\(3x-1=11x-1\)
\(3x-11x=-1+1\)
\(-8x=0\)
\(x=0:\left(-8\right)\)
\(x=0\)
a, \(5x-3x^2-4x-7x^2=0\)
\(\Leftrightarrow x-10x^2=0\Leftrightarrow x\left(1-10x\right)=0\Leftrightarrow x=0orx=\frac{1}{10}\)
b, \(5x-2x-1=3x+8x-1\)
\(\Leftrightarrow3x-1=11x-1\Leftrightarrow-8x=0\Leftrightarrow x=0\)
Vậy tập nghiệm của PT là S = { 0 } tương tự như a