12. Nine more than y is twenty one.​

y+9=21

Step-by-step explanation:

9 more than y equals 21.

Answer

y=12

Step-by-step explanation:

y+9=21   (this would be the formula)

 -9   -9   (you want to eliminate 9 from the equation, so subtract it from both sides of the equation)

y=12        (after subtracting 9 from both sides you are left with 12)

Check it

12+9=21  (is this true?)

21=21 (yes it is true, therefore y=12)

a) 7x=7

step-by-step explanation:

1.3

step-by-step explanation:

3x2=6   9x+6

bring down the 6 on both sides

6+6=12

12= 9x

divide by 9

12/9 =

1.3 =x