1, -5x + 2 = 14 <=> x = -12/5
2, <=> x^2 + 4x + 4 + x^2 - 2x + 1 = 2x^2 + 8x + 6
<=> 2x^2 + 2x + 5 = 2x^2 + 8x + 6 <=> -6x - 1 = 0 <=> x = -1/6
3, <=> 40x + 4 = 49x - 14 <=> 9x = 18 <=> x = 2
\(1,-5x+2=14\\ \Rightarrow-5x=12\\ \Rightarrow x=-\dfrac{12}{5}\\ 2,\left(x+2\right)^2+\left(x-1\right)^2=2\left(x+3\right)\left(x+1\right)\\ \Rightarrow x^2+4x+4+x^2-2x+1=2\left(x^2+3x+x+3\right)\\ \Rightarrow2x^2+2x+5=2\left(x^2+4x+3\right)\\ \Rightarrow2x^2+2x+5=2x^2+8x+6\\ \Rightarrow2x^2+8x+6-2x^2-2x-5=0\\ \Rightarrow6x+1=0\\ \Rightarrow6x=-1\\ \Rightarrow x=-\dfrac{1}{6}\)
