Select the correct answer.

Carly tutors students in math on the weekends and offers both thirty-minute sessions and sixty-minute sessions. She earns [tex]\$15[/tex] for each thirty-minute session and [tex]\$25[/tex] for each sixty-minute session.

If she earned [tex]\$230[/tex] this past weekend and had [tex]x[/tex] thirty-minute sessions and [tex]x-2[/tex] sixty-minute sessions, what is the value of [tex]x[/tex]?

A. 7
B. 5
C. 6
D. 8



Answer :

To find the value of [tex]\( x \)[/tex], which represents the number of thirty-minute sessions Carly conducted, follow these steps:

1. Set up the equations based on the given information.
- Carly charges \[tex]$15 for each thirty-minute session. - Carly charges \$[/tex]25 for each sixty-minute session.
- Her total earnings for the weekend were \$230.
- She conducted [tex]\( x \)[/tex] thirty-minute sessions.
- She conducted [tex]\( x - 2 \)[/tex] sixty-minute sessions.

2. Create an equation to represent her total earnings:
- Earnings from thirty-minute sessions: [tex]\( 15x \)[/tex]
- Earnings from sixty-minute sessions: [tex]\( 25(x - 2) \)[/tex]
- Total earnings: [tex]\( 15x + 25(x - 2) = 230 \)[/tex]

3. Simplify the equation:
[tex]\[ 15x + 25(x - 2) = 230 \][/tex]
Expand and simplify:
[tex]\[ 15x + 25x - 50 = 230 \][/tex]
Combine like terms:
[tex]\[ 40x - 50 = 230 \][/tex]

4. Isolate [tex]\( x \)[/tex]:
[tex]\[ 40x - 50 = 230 \][/tex]
Add 50 to both sides:
[tex]\[ 40x = 280 \][/tex]
Divide both sides by 40:
[tex]\[ x = 7 \][/tex]

Hence, [tex]\( x \)[/tex] is 7. Carly conducted 7 thirty-minute sessions.

The correct answer is:
A. 7