How do you solve #x-3y=4# and #-3x+5y=-14# using substitution?
1 Answer
Explanation:
First, we rearrange one of the formulae to give us
Now we can substitute in our value for
Then you expand the bracket and simplify it to find
#-3x + 5y = -14#
#-3 (4+3y) + 5y = -14#
(expand the brackets)
#-12 - 9y +5y = -14#
(simplify the
#-12-4y = -14#
(add
#-4y=-2#
(divide both sides by
#y=-2/-4#
#y = 0.5#
We then substitute the
Then we can use the other equation to check our answer.
So we know our answer is right!