2 times a number added to another number is 25. 3 times the first number minus the other number is 2 | MathCelebrity Forum

2 times a number added to another number is 25. 3 times the first number minus the other number is 2

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2 times a number added to another number is 25. 3 times the first number minus the other number is 20.

Let the first number be x. Let the second number be y. We're given two equations:
  1. 2x + y = 25
  2. 3x - y = 20
Since we have matching opposite coefficients for y (1 and -1), we can add both equations together and eliminate a variable.
(2 + 3)x + (1 - 1)y = 25 + 20

Simplifying, we get:
5x = 45

Typing this equation into the search engine, we get:
x = 9

To find y, we plug in x = 9 into equation (1) or (2). Let's choose equation (1):
2(9) + y = 25
y + 18 = 25

Typing this equation into our search engine, we get:
y = 7

So we have (x, y) = (9, 7)

Let's check our work for equation (2) to make sure this system works:
3(9) - 7 ? 20
27 - 7 ? 20
20 = 20 <-- Good, we match!
 
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