Answer:

Step-by-step explanation:
Since there are 20 students, this will be the denominator.
Now, to find how many students have a dog and a cat, you need to subtract all the numbers with 20. The leftover number will be the amount of students.
7+8+8=23
23-20=3
So, there are 3 students who have a dog and a cat.
So, the fraction will be 
Answer:
3
Step-by-step explanation:
Standard form is written in the order of the exponent <em>on</em><em> </em><em>a</em><em> </em><em>variable</em> from highest to lowest.
#1 exponents go 2, 1 , then zero. So, this is standard form.
#2 exponents go 2 then zero, so this is standard form.
#3 exponents go 1 then 2 then zero, so this is <em><u>not</u></em> in standard form.
#4 exponents go 3 to 2 to 1, so this is still in standard form.
hope this helps!
Answer:
A simple way to mentally subtract is to simplify the numbers, subtract, then subtract or add for the simplified answer.
Step-by-step explanation:
A simple way to mentally subtract is to simplify the numbers, subtract, then subtract or add for the simplified answer. For this 304 - 81 is easier as 300 - 80. Make note that we took away 4 from 304 and 1 from 81. Now we just subtract mentally, and 300 - 80 = 220. If we took 4 from 304, this means that our answer should be 4 less, since 4 less would be 304 - 80 = 216. If we took 1 from 81, then we add 1 back to get the equation 304 - 81 = 217.
304 - 81 = ?
300 - 80 = 220
304 - 80 = 216
304 - 81 = 217
Answer:
4
Step-by-step explanation: