For question 6 Make x for first one subject of formulae then it becomes x=-2y Substitution means replace your answer in the second part since x=-2y 3(-2y) +4y = 4 -6y+4y=4 -2y=4 y= 4/-2 y=-2
Now to find x,replace the answer for y in one in the equation so i replace y=-2 in the first part x=-2y x= -2(-2) x=4 Therefore x=4 and y=-2 To check your answer replace x and y by the values you got and check if you get same answer.
