How do you solve the following system: # 8x-7y=-39, 7x-2y= -67 #?

Question

1125 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-07-05T12:00:14

By arranging equations. #x=-391/33# and #y=-263/33#

Multiply the first equation by #-2# and the second by #7#:

#-16x + 14 y = 78#
#49x - 14 y = -469#

Add these equations (provided above), yielding

#49x-16x = -391#

#33x = -391#

#x = -391/33#

When you put this value for #x# (for instance in the first original equation), you will find #y#.

#8 xx(-391/33) - 7y = -39#

#-7y = -39 + (3128)/33#

#-7y = (-1287 + 3128)/33#

#-7y = 1841/33#

#y = -1841/231#

#y= -263/33#