Answer:
Step-by-step explanation:
Let's give their ages variables. Alex will be x and Annie will be y. You can solve via substitution.
x-y=12
x=2y+3
You solve the first equation by just moving the x to the right and dividing by -1, giving you y=x-12. After this, you substitute x-12 for y in the second equation.
x=2(x-12)+3
x=2x-24+3
x=2x-21
After this step, you'll wanna subtract 2x from both sides
x-2x=2x-21-2x
-x=-21
Then you want to divide by -1
x=21
Alex is 21, so we plug that back into our first equation.
21-y=12
-y=-9
(-y=-9)/1
y=9
When you've done that, you get Alex is 21 years old and Annie is 9.
(21,9)
Answer:Alex is 21 years old.
Annie is 9 years old.
Step-by-step explanation:
Let x represent Alex's age.
Let y represent Annie's age.
Alex’s age take away Annie’s age and you will get 12. This means that
x - y = 12
x = 12 + y - - - - - - - - - - - -1
Alex’s age is twice Annie’s plus three. This means that
x = 2y + 3 - - - - - - - - - - - - -2
Substituting equation 1 into equation 2, it becomes
12 + y = 2y + 3
2y - y = 12 - 3
y = 9
Substituting y = 9 into equation 1, it becomes
x = 12 + 9 = 21
