Explanation:
Hi there,
The sum of two numbers is 8.
x + y = 8
If three times the first number
is equal to the second number.
3x = y
Replace the y in top equation with 3x
x + 3x = 8
4x = 8
x = 2
Substitute x = 2 in first equation
x + y = 8
2 + y = 8
y = 8 - 2
y = 6
{2,6}
Hope this helps :-)