Question

(Solve algebraically) One number is 3 more than twice the other number.
If the sum of the two numbers is 21, find the two numbers.
(Use a comma to separate answers as needed)

Answer 1

So in this problem you are given two unknowns s o you will need 2 equations to solve

Answer 2

one number we will call x the other number we will call y

Answer 3

x = 3+2y
and
x+y=21

Answer 4

So we can use x=3+2y and plug it into the x+y =21 equation

Answer 5

(3+2y)+y = 21

Answer 6

3+3y=21
3y=18
y=6

Answer 7

And now we have y so just plug it into the x+y= 21 formula again to find x :)

Answer 8

got it! thank you very much!

Answer 9

if you have any more questions about feel free to ask