Question 1068265
Let {{{ a }}} = the cost of a  table 
Let {{{ b }}} = the cost of a chair
-------------------------------
(1) {{{ 2a + 3b = 200 }}}
(2) {{{ 3a + 2b = 250 }}}
----------------------
Multiply both sides of (1) by {{{ 3 }}}
Multiply both sides of (2) by {{{ 2 }}}
Subtract (2) from (1)
---------------------------
(1) {{{ 6a + 9b = 600 }}}
(2) {{{ -6a - 4b = -500 }}}
---------------------------
{{{ 5b = 100 }}}
{{{ b = 20 }}}
and
(1) {{{ 2a + 3b = 200 }}}
(1) {{{ 2a + 3*20 = 200 }}}
(1) {{{ 2a = 140 }}}
(1) {{{ a = 70 }}}
---------------------
One table costs $70
One chair costs $20
----------------------
check:
(1) {{{ 2a + 3b = 200 }}}
(1) {{{ 2*70 + 3*20 = 200 }}}
(1) {{{ 140 + 60 = 200 }}}
(1) {{{ 200 = 200 }}}
OK you can check (2)