Your answer would be 7
(7 x2)=14
(7 x 1)= 7
14 + 7=21
(2+1)=3
21=3(x)
21/3=7
x=7
Hope this helps :)
Well 7 * 2 is 14 and 7 * 1 is 7 so 14 + 7 is 21. That means the other side of the equation has to equal 21.
2 + 1 is 3 and 21/3 is 7 so the number 7 goes in the blank
Hope this helps!!