Answer: 
or 
Step-by-step explanation:
For this exercise you can convert the mixed number to an improper fraction:
1. Multiply the whole number part by the denominator of the fraction.
2. Add the product obtained and the numerator of the fraction (This will be the new numerator).
3. The denominator does not change.
Then:
You know that he had 30 minutes in time-out, he counted spots on the ceiling for 
minutes and the rest of the time he made faces at his stuffed tiger.
Then, in order to calculate the time Calvin spent making faces at his stuffed tiger, you need to subract 30 minutes and minutes:
or
Answer:
OA and OC hope that helps :)
There's 9 choices for the first digit and 4 choices for the last digit. The number of choices for the 2nd and 3rd digits is 90 if 2 numbers are different. or 100 if duplicates are allowed.
If duplicates are allowed the answer is 9 * 100 * 4 = 3600 possible numbers.
(y -3)^2 = 4y - 12
Expand.
(y-3)(y -3) = 4y - 12
y² - 6y + 9 = 4y - 12
y² - 6y -4y + 9 + 12 = 0
y² - 10y + 21 = 0
Factors are -7y and - 3y
y² - 10y + 21 = 0
y² - 3y - 7y + 21 = 0
y(y - 3) -7(y - 3) = 0
(y - 3)(y - 7) = 0
y-3 = 0 or y - 7 = 0
y = 0 + 3 or y = 0 + 7
y = 3 or 7
