How do you solve the system of equations #y=9# and #7x-6y=-12#?

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Answer 1 · 2018-01-25T12:05:10

See a solution process below:

Because the first equation is already solved for #y# we can substitute #9# for #y# in into the second equation and solve for #x#:

#7x - 6y = -12# becomes:

#7x - (6 xx 9) = -12#

#7x - 54 = -12#

#7x - 54 + color(red)(54) = -12 + color(red)(54)#

#7x - 0 = 42#

#7x = 42#

#(7x)/color(red)(7) = 42/color(red)(7)#

#(color(red)(cancel(color(black)(7)))x)/cancel(color(red)(7)) = 6#

#x = 6#

The solution is:

#x = 6# and #y = 9#

Or

#(6, 9)#