Question 329182
(1) {{{4x+3= -3y}}}
(2) {{{-x/7 + 4y/21= 1}}}
first, I will get (1) into the same form as (2)
(1) {{{ 4x + 3y = -3}}}
Then I multiply both sides of (2) by {{{21}}}
(2) {{{-3x + 4y = 21}}}
Now I multiply both sides of (1) by {{{3}}}
(1) {{{ 12x + 9y = -9}}}
Now I multiply both sides of (2) by {{{4}}}
(2) {{{-12x + 16y = 84}}}
Now I add (1) and (2)
{{{25y = 75}}}
{{{y = 3}}}
Then I substitute this result back into (1)
(1) {{{4x+3= -3y}}}
 {{{4x+3= -3*3}}}
{{{4x = -3 - 9}}}
{{{4x = -12}}}
{{{x = -3}}}
The answer is (-3,3)