Question 581052
(1) {{{ y =.15x + 18000 }}}
(2) {{{ y =.11x + 20000 }}}
I can substitute (1) directly into (2)
{{{ .15x + 18000 = .11x + 20000 }}}
Subtract {{{ .11x }}} from both sides
{{{ .04x + 18000 = 20000 }}}
Subtract {{{ 18000 }}} from both sides
{{{ .04x = 2000 }}}
Divide both sides by {{{ .04 }}}
{{{ x = 2000/.04 }}}
{{{ x = 50000 }}}
Now plug this vfalue of {{{ x }}} into (1) or (2)
(1) {{{ y =.15*50000 + 18000 }}}
(1) {{{ y = 7500 + 18000 }}}
(1) {{{ y = 25500 }}}
The solution is ( 50000,25500 )
check:
(2) {{{ y =.11*50000 + 20000 }}}
(2) {{{ y = 5500 + 20000 }}}
(2) {{{ y = 25500 }}}
OK