Respuesta :
Let x = the older student
Let y = the younger student
Let z = the teacher.
x = 2y
z = 5x
z + 5 = 5y Somehow this does not look like its going to be nice.
z = 5y - 5
Since z = 5y - 5 we have
5y - 5 = 5x
y - 1 = x Here's the problem. there is a contradiction. You need to make y bigger, not smaller.
Let y = the younger student
Let z = the teacher.
x = 2y
z = 5x
z + 5 = 5y Somehow this does not look like its going to be nice.
z = 5y - 5
Since z = 5y - 5 we have
5y - 5 = 5x
y - 1 = x Here's the problem. there is a contradiction. You need to make y bigger, not smaller.
Answer: 40 years old
Step-by-step explanation:
Let's call the younger student's age A and the older student's age B. The teacher's age will be T.
B = 2A
T = 5B
T+5 = 5(A+5)
Simplify the last equation.
T+5 = 5A+25
T = 5A+20
Now we have two equations solved for T, so we can set them equal to each other.
5B = 5A + 20
We can plug 2A in for B
5(2A) = 5A + 20
10A = 5A + 20
5A = 20
A = 4
To find T, we plug 4 in for A in T = 5A + 20
T = 5(4) + 20
T = 40
The answer is 40 years old.