4x+9y=59.5 and x+y=8. Find the values of x and y.

Firstly, take the second equation and make either x or y the subject, which means to make it either x equals or y equals. To make x the subject, we take y away from both sides giving x=8-y. Then, substitute this into the first equation.

Substitution would give 4(8-y)+9y=59.5 Multiplying out gives 32-4y+9y=59.5 Then take away 32 from each side and bring together the y values to get 5y=27.5 We then divide by 5 to get y=5.5

Now we know the value of y, we can use either equation to work out x. x+5.5=8, therefore x=2.5