Question 569457
(1) {{{ 4x+3y=10 }}} 
(2) {{{ y=2x }}}
Substitute (2) into (1)
(1) {{{ 4x + 3*(2x) = 10 }}}
(1) {{{ 4x + 6x = 10 }}}
(1) {{{ 10x = 10 }}}
(1) {{{ x = 1 }}}
and, since
(2) {{{ y = 2x }}}
(2) {{{ y = 2*1 }}}
(2) {{{ y = 2 }}}
So, the solution is ( 1,2 )
Here's a plot of the lines
{{{ graph( 400, 400, -6, 6, -6, 6, 2x, -(4/3)*x + 10/3 ) }}}