+12
2
It is: (15-7)*(12-9) = 24
7 x 5 = 35 7 + 5 = 12
Add the integer values and apply the common sign. For example +5 and +7 : 5 + 7 = 12 so + 12 -5 and - 7: 5 + 7 = 12 so - 12
7 add 7 add 7 then you take away 12
To get 1, you need 12 twelfths. If you have 7/12 you have to add 5/12 to get to 12/12 = 1(7 + 5 = 12, 7/12 + 5/12 = 12/12 = 1)
+12
5 and 7 are both prime numbers that add up to 12
2
30
7/12
It is: 10
five twelfths 7/12 + 5/12 = (7 + 5)/12 = 12/12 = 1/1 = 1
19
19
It is: (15-7)*(12-9) = 24