Answer:
12 and 8
Step-by-step explanation:
SOLUTION:
Let:
x = first number
y = second number
The sum of the two numbers is 20
x + y = 20 (Equation 1)
The difference of the two numbers is 4
x - y = 4 (Equation 2)
Two equations two unknowns
Using substitution method:
in equation 2, isolate x
x - y = 4
x = 4 + y (Equation 3)
Substitute equation 3 in equation 1
x + y = 20
(4 + y) + y = 20
Simplify and solve for y
4 + 2y = 20
2y = 20 - 4
2y = 16
y = 16/2
y = 8
Substitute the value of y in equation 3
x = 4 + y
x = 4 + 8
x = 12
CHECKING:
For equation 1:
x + y = 20
12 + 8 = 20
20 = 20 âś“
For equation 2:
x - y = 4
12 - 8 = 4
4 = 4 âś“
Therefore, the two numbers are 12 and 8 (ANSWER)
