For these problems you have to use PEMDAS so for problem 15 you would do the parentheses first, (21-3) you get 18 and then exponents, 3^2, you get 9, no multiplication but there is division so take your answers, 18 and 9 and divide them, you get 2, so the answer to 15 is 2.
If the total bill is $85, and you want to leave a 15% tip, then you can calculate it as follows:
85 * 15%
= 85 * 15/100
= 85 * 0.15
= 12.75
The amount that should be left as a tip is D. $12.75.
4w +8. C.
It’s 4 * width for perimeter and two of the sides are longer by 4in so 2*4=8
Answer:
3
Step-by-step explanation:
6 times 3 equals 18
Answer:
720 ways
Step-by-step explanation:
Generally, combination is expressed as;

The question consists of 9 multiple-choice questions and examinee must answer 7 of the multiple-choice questions.
⇒ ⁹C₇ 

= 36
The question consists of 6 open-ended problems and examinee must answer 3 of the open-ended problems.
⇒ ⁶C₃ 

= 20
Combining the two combinations to determine the number of ways the questions and problems be chosen if an examinee must answer 7 of the multiple-choice questions and 3 of the open-ended problem.
⁹C₇ × ⁶C₃
= 36 × 20
= 720 ways