One more than 3 times a number is the same as 5 times the number, decreased by 15. Find the number.

• Assign the variable
• Write an equation
• Solve equation

3 answers

x = variable

3x + 1 = 5x - 15

16 = 2x

? = x
1 + 3x = 5x - 15

1 + 3x-3x = 5x-3x - 15

1 = 2x - 15

1+15 = 2x - 15+15

16 = 2x

16/2 = 2x/2

8 = x or x = 8
3p+1 = 5p-15

3P+ 1+15 = 5P -15 +15
3p +16 = 5p
3p-3p+16 = 5p -3p

16 = 2p

p = 8