Let the first number be "x", and the 2nd number (which is twice as large as the other), be 2x.
Set the equation
2x + x = 36
Simplify. Combine like terms
(2x + x) = 36
3x = 36
Isolate the x. Divide 3 from both sides
(3x)/3 = (36)/3
x = 36/3
x = 12
The first number is 12
The second number is 2x. Replace x with 12. Multiply.
2x = 2(12) = 24
The second number is 24
Check: 12 + 24 = 36 (True)
Answer: 12 & 24
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