How do you solve the system of equations #-8x + 12y = 4# and #- 10x - 2y = 22#?

1 Answer
Jclass
Apr 21, 2018

You need to use simultaneous equations.

Explanation:

I prefer substitution but other ways will work. Take one of the equations and solve for either x or y. Then substitute the value for x or y into the second equation.

e.g.
#x-2y=7 # and # 2x+7y = -8#

#x-2y=7 # Solve for x
#x=7+2y# Sub this into equation 2

#2(7+2y)+7y = -8# Solve for y
#14+4y+7y = -8#
#11y=-22#
#y=-2#

From above
#x = 7 +2y# (we now know y = -2)
#x = 7+2(-2)#
#x = 3#

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