To correctly evaluate this problem, apply the standard orders of operations rules. Therefore, you must first divide: 

\(\displaystyle -\frac{15}{5}=-3\)

Then find the sum of: 

\(\displaystyle -20+-3=-23\)

To solve this problem first apply the distributive property then combine the like terms:

\(\displaystyle -3(3x-9)-5=-9x+27-5=-9x+22\)

To determine how much money Cara spent at the store, find the difference between the amount of money she started with and the amount of money she had after shopping. 

Thus, the solution is: 

\(\displaystyle 15-3.75=11.25\)

If Betty has \(\displaystyle \$34.56\) in her wallet and buys a sandwich that costs \(\displaystyle \$8.46\), the best way to determine how much money is left in her wallet is to subtract \(\displaystyle \$8.46\) from \(\displaystyle \$34.56\). 

An easy way to do this is to first subtract \(\displaystyle 34\) and \(\displaystyle 8\). This results in: \(\displaystyle 34-8=26\). 

Next, \(\displaystyle 0.46\) should be subtracted from \(\displaystyle 0.56\). This results in: \(\displaystyle 0.56-0.46=.10\)

\(\displaystyle 26+.10=26.10\)

Therefore, Betty will have \(\displaystyle \$26.10\) left in her wallet. 

First you subtract the values in the ones place, 

\(\displaystyle 7-2=5\).  

Then you subtract the tens values, 

\(\displaystyle 30-10=20\).  

Put those two together and you get your answer of \(\displaystyle 25\).

10 percent off means a discount of $5 and a final price of $45. 

$10 off means a final price of $40. 

5 percent off means a discount of $2.50 and a final price of $47.50.

Thus, $10 off is the best deal.  

The phrase 'a quarter before' indicates that the time is 15 minutes before the hour. 

The bus picks Thomas up at

"a quarter before 8"

which translates to 15 minutes before 8 o'clock, or

7:45 AM.

Because it takes half an hour, or

30 minutes

to get to school, Thomas will arrive at school 30 minutes after 7:45 AM.

7:45 AM + 30 minutes =

8:15 AM

'a quarter after' indicates that the time is 15 minutes after the hour, so 8:15 can be read as 

a quarter after 8.

Note that there are 60 minutes in one hour.

The key word, "approximately," indicates that we must round each of these values. Let's round to the nearest tens place because each of our answer choices is rounded to the tens place.

Shoes cost $42.64. 

$42.64 rounded (down) to the nearest tens place is $40.

Pants cost $37.99.

$37.99 rounded (up) to the nearest tens place is $40.

A shirt costs $21.34.

$21.34 rounded (down) to the nearest tens place is $20.

Let's add up our estimated prices.

$40 + $40 + $20 =

$100.

Add the first two numbers as follows:

\(\displaystyle -34 + 87 = +(87-34) = 53\)

Now add this sum to the third number as follows:

\(\displaystyle 53+ (-63) = -(63-53) = -10\)

Add the first two numbers as follows:

\(\displaystyle -34 + 67 = +(67-34) = 33\)

Now add this sum to the third number as follows:

\(\displaystyle -34 + 67 + (-23) = 33 + (-23) = +(33-23) = 10\)