Question

Complete the solution of the equation. Find
the value of y when x equals 12.
x + 3y = 21

Answer 1

when x=12, y = 3

y= 3 because

if you substitute 12 for x then you get
12+ 3y =21
you subtract 12 from each side and you get 3y =9 then you divide each side by 3 and you get y=3

Answer 2

y=3

Explanation:

12+3y=21

-12 -21 subtract 12 from both sides

------------------

3y=9

divide 3 from y and 9, so you can get y by itself

3y/3= y 9/3= 3

so y is equal to 3