Answer: 9 elm trees were removed.
Step-by-step explanation:
Let x represent the number of elm trees removed.
The total number of elm trees in the park is 22. Elm leaf beetles have been attacking the trees. After removing several of the diseased trees, there are 13 healthy elm trees left. The equation to find the number of elm trees that were removed would be
x + 13 = 22
Subtracting 13 from the left hand side and the right hand side of the equation, it becomes
x + 13 - 13 = 22 - 13
x = 9
Answer:
2a could be combined with 5a
Step-by-step explanation:
they both have an (a) after them
thanks for your help I really think that it's three
The first one would be x^12
Answer:
There are 400 possible zip codes in the Houston area
Step-by-step explanation:
Here, we want to calculate the possible number of zip codes in the Houston area
We have 5 digits to form
77 is the first two digits ( this is fixed)
For the third digit, we are selecting 1 number out of 0,3,4 or 5
This means 4 C 1
The remaining digits can be any digits
We have 0-9, a total of 10 digits
The first will be 10 C 1 and the second last digit too is 10 C 1
So the number of possible zip codes will be;
4 C 1 * 10 C 1 * 10 C 1
= 4 * 10 * 10 = 400 possible zip codes
