[tex]5y+2x = -7~~~~~......(i)\\\\y = -2x +5 ~~~~~~.....(ii)\\\\(i) -(ii):\\\\5y+2x -y = -7-(-2x+5)\\\\\implies 4y +2x = -7 +2x -5\\\\\implies 4y +2x -2x = -12\\\\\implies 4y = -12\\\\\implies y = - \dfrac{12}4 = -3\\\\\\\text{Substitute}~ y=-3~ \text{in equation (ii):}\\\\\\-3 = -2x +5\\\\\implies 2x = 5 +3 \\\\\implies 2x = 8\\\\\implies x = \dfrac 82 =4\\\\\text{Hence,}~ x = 4[/tex]
