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Answer 1 · 2018-01-07T23:10:47

Substitution means putting in a value in place of another, so let's give it ago.

#x=4#, #y=0#

We know that both equations consist of two variables,#x# and #y#. Therefore, here we will be subbing either variable in, in place of the other.

In all honesty, you can go either way however as we can make a nice equation for #x#, that seems like the easier way to go.

So we need to rearrange #x+5y=4# into #x=4-5y#

Now we have an equation for x, so whenever we see in an #x# in the other equation , we sub this new equation in. By doing this we can find #y#.

#therefore# #2(4-5y)+10y = 8#
#therefore# #8-10y+10y=8#
#8=8# #therefore y =0#

Now we find #x# by subbing #y=0# into one of the equations #therefore# #x+5(0) =4 #
#x=4#.