Solve these simultaneous equations 2y+x=8, 1+y=2x.

When solving simultaneous equations the first step is to take one of the equations and rearrange it to make one of the terms the subject. In this case lets take the equation 1+y=2x. Take the 1 over to the other side to make y the subject. y=2x-1. The next step is to substitute the expression for the term you have just worked out into the other equation that you didn't use at the beginning. In our case this gives us 2(2x-1)+x=8. Expand the brackets: 4x-2+x=8. Collect like terms: 5x=10. Simplify: x=2. Now we have one of the unknown values, we can substitute it back into one of the original equations to work out the final unknown. In our case: 1+y=2(2). Expand the brackets: 1+y=4. Collect like terms: y=3. Now we have both the answers x=2, y=3. You can check you answers by substituting the values back into the original equations and see if the two sides equal each other. 2(3)+(2)=8. 8=8. The answer is correct.