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18 votes
18 votes
A student chose a number, multiplied it by 2, then subtracted 138 from the result and got 102. What was the number he chose?

User Julien Ambos
by
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2 Answers

19 votes
19 votes
Answer: 120

2x - 138 = 102
+138 +138
(x=the missing number)

2x =240

240\2 = 120

x=120
User Jakobht
by
2.8k points
27 votes
27 votes

Answer:

51

Explanation:

let's set the starting number as x

1. x times 2 = 2x

2. 2x- 138

3. result = 102

So, 2x-138 = 102

Now lets work backwards to solve for x.

1. 2x = 102

x = 51

So the starting number was 51.

User Marrossa
by
2.8k points