Step 1 - through previous experience realise this equation can be solved by the substitution methodStep 2 - rearrange for the part you want to sub in, in this case it is done for us as Y is the variable we will sub inStep 3 - where there is a y in the equation replace it with 6x +2 this gives us 4x + 7(6x +2) = 336Step 4 - expand the brackets 4x + 42x + 14 = 336Step 5 - collect like terms to get 46x = 322Step 6 - divide through by 46 to find the value of x, x = 7