Let x be the number of months.
The first plan is 15 dollars sign up fee and 38 dollars per month. So the equation is 38x + 15.
The second plan is 78 dollars as sign up fee and 31 dollars per month. So the equation is 31x + 78.
We need find when x has the same value in both equations, so we do their equality:
38x + 15 = 31x + 78
Let's subtract 15 from both sides
38x + 15 = 31x + 78
38x + 15 - 15 = 31x + 78 - 15
38x = 31x + 63
Now let's subtract 31x from both sides to have the variables on a side and the numbers on side:
38x = 31x + 63
38x - 31x = 31x - 31x + 63
7x = 63
Divide both sides by 7 to have the variable x on a side and its value on the other:
(7x)/7 = 63/7
x = 9
So at month 9, the 2 plans will cost the same.
Let's check our answers, and let y be the cost:
y = 38x + 15 = 38*9 + 15 = 357
y = 31x + 78 = 31*9 + 78 = 357
Our answer has been approved.
Hope this helps! :D
Answer:
He could have asked the girls as well, and could have asked the entire class instead of just 10 students.
Step-by-step explanation:
By only asking 10 boys, he is not getting a complete representation of the whole class, as their are 30 students in the class.
#6 80, 162.5
#7 .375, .4 repeating
Problem
Solution
For this case we want to find the domain for this case and we can analyze the denominator on this case because cannot be equal to 0, so we can set up this:
If we factorize we got:
(X-3)(x+2)=0
So then we have X=3 and X=-2
With these results we can conclude that the value of x cannot be 3 or -2 because then the function will be not defined
And the best solution is:
A. all real numbers except -2 and 3
