Question 24435
Solve by substitution:
1) {{{2x+y = 7}}} Write this in terms of y:
1a){{{y = -2x+7}}} and substitute into equation 2) then solve for x. 
2) {{{5x-2y = 4}}}

{{{5x-2(-2x+7) = 4}}} Simplify and solve for x.
{{{5x+4x-14 = 4}}}
{{{9x-14 = 4}}} Add 14 to both sides of the equation.
{{{9x = 18}}} Divide both sides by 9.
{{{x = 2}}} Now substitute this value of x into equation 1a) and solve for y.

{{{y = -2x+7}}}
{{{y = -2(2)+7}}}
{{{y = -4+7}}}
{{{y = 3}}}

The solution is: (2, 3)
Here's the graphical solution: Red line is:{{{y = -2x+7}}} Green line is:{{{y = (5/2)x-2}}}
{{{graph(300,200,-5,5,-5,8,-2x+7,(5/2)x-2)}}}