\(\left(3x+4\right)^2+\left(4x-1\right)^2+\left(2+5x\right)\left(2-5x\right)=25\)
\(\left(3x\right)^2+2\times3x\times4+4^2+\left(4x\right)^2-2\times4x\times1+1^2+2^2-\left(5x\right)^2=25\)
\(9x^2+24x+16+16x^2-8x+1+4-25x^2=25\)
\(\left(9x^2+16x^2-25x^2\right)+\left(24x-8x\right)=25-16-1-4\)
\(16x=4\)
\(x=\frac{4}{16}\)
\(x=\frac{1}{4}\)
\(\left(3x+4\right)^2+\left(4x-1\right)^2+\left(2+5x\right)\)\(\left(2-5x\right)=25\)
\(\Rightarrow\left(9x^2+24x+16\right)+\left(16x^2-8x+1\right)+\left(4-10x+10x-25x^2\right)=25\)
\(\Rightarrow9x^2+24x+16+16x^2-8x+1+4-10x+10x-25x^2=25\)
\(\Rightarrow\left(9x^2+16x^2-25x^2\right)+\left(24x-8x-10x+10x\right)+\left(16+1+4\right)=25\)
\(\Rightarrow16x+21=25\Rightarrow16x=25-21\Rightarrow16x=4\Rightarrow x=0,25\)
