11 * 11 = 121. The star means multiply btw.
1st box: 2a (subtract 2a from both sides)
2nd box: 3 (add 3 to both sides)
3rd box: 10 (add 7+3)
4th and 5th box: 2 (divide both by 2)
6th box: 5 (10/2=5)
True y=2x+1 and y-3x=4 it would be the same way because you can solve for x and you can solve for y
The answer is 8...............
