Answer:
Like terms are terms whose variables are the same.
We can only add them because if they does not have the same variable you do not actually know if the variables are equivalent and you will get the wrong answer.
Step-by-step explanation:
Ex: 4z,7z,108z,45z
Ex: 4w-2h+7a-2w
You can not add 4w and 7a because you do not know what the variables equal so you do not know the true number so add or subtract by.
Answer:

Step-by-step explanation:

Let's solve the second equation for a to later on replace it in the first equation.

Now plug this into the first equation.

Distribute the 9

Break down the fraction.

Simplify.

Subtract 

Combine like terms.



Muliply by the reciprocal or inverted fraction next to b.


Now plug this value into any of the equations to find the value of a.

Answer:
The answer is 58 degrees.
Answer:
B
Step-by-step explanation:
Note:
1 gal = 4 quarts
1 pint = 0.5 quart
Re-writing all the choices in dollars and quarts and calculating how much each quart costs
A) $1 per 1 quart
B) $2 per gallon = $2 per 4 quarts = $2 ÷ 4 quarts = $0.50 per quart
C) $1.50 per 2 quarts = $1.50 ÷ 2 quarts = $0.75 per quart
D) $0.50 per 1 pint = $0.50 per 0.5 quart = $0.50 ÷ 0.5 quart = $1 per quart
If you compare all of the above, it is clear that answer B ($0.50 per quart) is the cheapest rate and hence the best deal.