A first number plus twice a second number is 6. Twice the first number plus the second totals 9. Find the numbers

To figure out the answer to this problem you have to start by noticing that the equations are 'x+2y=6' and '2x+y=9'. Now take 2x+y=9 and subtract 2x from both sides. now y=9-2x so you can substitute y into the first equation. x+2 (9-2x) = 6. Distribute 2 by the 9 and - 2x and you get x+18-4x=6. Add like terms and now you have - 3x+18=6. Subtract 18 from both sides and you get - 3x=-12 now divide - 3 from both sides and you get 4=x. Now substitute 4 in for one of the equations 2 (4) + y=9 and 2*4 is 8 so now you have 8+y=9 now you subtract 8 from both sides and you find the y=1 and x=4.