Question 441827


{{{12x + 7y = 19}}} and 

{{{4x - y = 3}}}...solve the system
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{{{4x - y = 3}}}......solve for {{{y}}}

{{{4x - 3 = y}}}......substitute in {{{12x + 7y = 19}}} and solve for {{{x}}}


{{{12x + 7(4x - 3)= 19}}}

{{{12x + 28x - 21= 19}}}

{{{40x = 19+21}}}

{{{40x = 40}}}

{{{x =1}}}....now find {{{y}}}

{{{y=4x - 3 }}}

{{{y=4*1 - 3 }}}

{{{y=1 }}}

 then the value of {{{8x + 8y=8*1+8*1=8+8=16}}}