243,070 views
21 votes
21 votes
5. Three times a number, decreased by 8, is the same as twice the number,

increased by 15. Find the number.

User Juanjo
by
2.8k points

2 Answers

15 votes
15 votes

Answer:

x = 23

Explanation:

First, let's turn this into an equation:

three times a number (3x), decreased (-) by 8 is the same (=) as twice the number (2x) increased (+) by 15.

3x - 8 = 2x + 15

Now lets solve:

3x - 8 = 2x + 15

Add 8 to each side:

3x = 2x + 23

subtract 2x from each side:

x = 23

Substitute to check:

3x - 8 = 2x + 15

3 ( 23 ) - 8 = 2 ( 23 ) + 15

69 - 8 = 46 + 15

61 = 61

User Soojin
by
3.4k points
29 votes
29 votes

Answer:

23

Explanation:

3x - 8 = 2x + 15

Add 8 to both sides

3x = 2x + 23

Subtract 2x from both sides

x = 23

User Fumiko
by
2.8k points