Question

Find the value of two numbers if their sum is 21 and their difference is 5

Answer 1

Answer: x = 13 and y = 8

Step-by-step explanation:

Two numbers must add to 21. We don't know them yet, so let's just use a placeholder for both of them for now.

x + y = 21

Their difference is five, meaning that if we subtract one from the other, we get five. Again, we don't know the numbers yet, so we'll add a placeholder for now.

x - y = 5

We can now solve a system of equations for x.

x = y + 5

y + 5 + y = 21

2y + 5 = 21

2y = 16

y = 8

x - 8 = 5

x = 13

So x = 13 and y = 8