An animal shelter spends $3.50 per day to care for each bird and $4.00 per day to care for each cat. Katherine noticed that the shelter spent $103.50 caring for birds and cats on Friday. Katherine found a record showing that there were a total of 28 birds and cats on Friday. How many birds were at the shelter on Friday?
No. of birds X
No. of cats 28 - X
103.50 = 3.50X + 4.00(28 - X) = 3.5X + 4x28 - 4X = 3.5X + 112 - 4X
O.5X = 112 - 103.5 = 8.5
X = 17
No. of birds 17
No. of cats 28 - X + 28 - 17 = 11
Check: $3.5 x 17 + $4 x 11 = $59.5 + $44 = $103.50
Answer: 
Step-by-step explanation:
To solve this exercise it is important to remembet the definition Definition of a Logarithm:
If
and, 
, then
is equivalent to
(which is the exponential form).
Knowing this definition and having the following logarithmic equation:

You can identify that:

Therefore, susbtituting values into
, you can rewrite this equation as an exponential equation. Then:

Answer:
34
Step-by-step explanation:
Marcy got 15% of the 40 wrong
.15 *40
6
If she got 6 wrong, then she got the rest right
40-6 = 34
She got 34 right
The answer is 8 + x > 5An equation or an inequality that contains at least one variable is called an open sentence.
When you substitute the variable in an open sentence with a number the resulting statement is either true or false. If the statement is true the number is a solution to the equation or inequality.