Step 1) Because the second equation is already solved for #y# we can substitute #(5x - 7)# for #y# in the first equation and solve for #x#:
#3x - y = -6# becomes:
#3x - (5x - 7) = -6#
#3x - 5x + 7 = -6#
#(3 - 5)x + 7 = -6#
#-2x + 7 = -6#
#-2x + 7 - color(red)(7) = -6 - color(red)(7)#
#-2x + 0 = -13#
#-2x = -13#
#(-2x)/color(red)(-2) = (-13)/color(red)(-2)#
#(color(red)(cancel(color(black)(-2)))x)/cancel(color(red)(-2)) = 13/2#
#x = 13/2#
Step 2) Substitute #13/2# for #x# in the second equation and calculate #y#:
#y = 5x - 7# becomes:
#y = (5 * 13/2) - 7#
#y = 65/2 - (2/2 xx 7)#
#y = 65/2 - 14/2#
#y = 51/2#
The Solution Is: #x = 13/2# and #y = 51/2# or #(13/2, 51/2)#
