It's a simultaneous equation:
Steps:
1.Number the equations..
a+b=77 -1
a-b=13 -2
2. Choose what variable you want to use. In this case I would use the "b". Since the signs in front of the "b's" are different, add the two equations together
a + b = 77
+ + +
a (-b) = 13
Which gives;
2a = 90
Then solve to find a:
2a=90
a= 90/2
a=45
3.Then plug the "a" value into any of the original equations to find the "b" value. I would use equation 1 since the all the variables are positive.
a + b = 77
(45) + b = 77
b=77-45
b=32
4.Solution
a=45
b=32
Answer:
3 pints = 6 cups
Step-by-step explanation:
Formula: multiply the volume value by 2
Answer:
Let total number of dog and cat population in animal shelter be x.
As per the statement:
An animal shelter has 9 puppies.
⇒ Total number of puppies = 9
It is also given that if the puppies are 36% of the total dog and cat population.
⇒ 
or

By cross multiply we get;

Divide both sides by 36 we get;

Therefore, total number of dogs and cat population in animal shelter are 25
Answer:
Hannah is deciding between two truck rental companies. Company A charges an initial fee of $30 for the rental plus $2 per mile driven. Company B charges an initial fee of $100 for the rental plus $1 per mile driven. Let AA represent the amount Company A would charge if Hannah drives xx miles, and let BB represent the amount Company B would charge if Hannah drives xx miles. Write an equation for each situation, in terms of x,x, and determine the interval of miles driven, x,x, for which Company A is cheaper than Company B.