\begin{cases} y=4x-2\\x^2+(4x-2)^2-x(4x-2)=3 \end{cases}=> \\ \\=>\begin{cases} y=4x-2\\x^2+16x^2-16x+4-4x^2+2x-3=0 \end{cases}=> \\ \\=>\begin{cases} y=4x-2\\13x^2-14x+1=0 \end{cases} \\ \\ \\D=(-14)^2-4*13*1=144 \\x_1=\frac{1}{13} \\x_2=1 \\ \\\begin{cases} x_1=\frac{1}{13}\\y_1=4*\frac{1}{13}-2\\x_2=1\\y_2=4*1-2 \end{cases}=>\begin{cases} x_1=\frac{1}{13}\\y_1=-\frac{22}{13}\\x_2=1\\y_2=2 \end{cases}" alt="\begin{cases} 4x-y=2\\x^2+y^2-xy=3 \end{cases} =>\begin{cases} y=4x-2\\x^2+(4x-2)^2-x(4x-2)=3 \end{cases}=> \\ \\=>\begin{cases} y=4x-2\\x^2+16x^2-16x+4-4x^2+2x-3=0 \end{cases}=> \\ \\=>\begin{cases} y=4x-2\\13x^2-14x+1=0 \end{cases} \\ \\ \\D=(-14)^2-4*13*1=144 \\x_1=\frac{1}{13} \\x_2=1 \\ \\\begin{cases} x_1=\frac{1}{13}\\y_1=4*\frac{1}{13}-2\\x_2=1\\y_2=4*1-2 \end{cases}=>\begin{cases} x_1=\frac{1}{13}\\y_1=-\frac{22}{13}\\x_2=1\\y_2=2 \end{cases}" align="absmiddle" class="latex-formula">