How do you solve the system of equations #3x - 4y = - 4# and #9x - 10y = 2# using elimination?

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Answer 1 · 2017-09-28T14:53:14

x=8 and y=7

You need to have the same number of x's or y's in each equation so then you can subtract the equations from each other 'eliminating' the x's or y's

If we multiply the first equation by 3 we get

#9x-12y=-12#

We can now subtract the second equation from this to get

#9x-12y=-12#
#-#
#9x-10y=2#

#-2y=-14#

Divide by -2

#y=7#

Substitute in to a previous equation

#9x-10(7)=2#

And simplify

#9x-70=2#

#9x=72#

#x=8#