How do you solve the system of equations #y= 1x+4# and #y=8x-3#?

1 Answer
Jan 30, 2017

See the entire solution process below:

Explanation:

Because the first equation is already solved for #y#, substitute #1x + 4# for #y# in the second equation and solve for #x#:

#1x + 4 = 8x - 3#

#1x + 4 - color(red)(1x) + color(blue)(3) = 8x - 3 - color(red)(1x) + color(blue)(3)#

#1x - color(red)(1x) + 4 + color(blue)(3) = 8x - color(red)(1x) - 3 + color(blue)(3)#

#0 + 7 = 7x - 0#

#7 = 7x#

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

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

#1 = x#

#x = 1#

Step 2) Substitute #1# for #x# in the first equation and calculate #y#:

y = (1 xx 1) + 4#

#y = 1 + 4#

#y = 5#

The solution is:

#x = 1# and #y = 5#