Answer:
For a monthly cost of at least $7 and at most $8, you can have between 100 and 110 calling minutes.
Step-by-step explanation:
The problem states that the monthly cost of a celular plan is modeled by the following function:
In which C(x) is the monthly cost and x is the number of calling minutes.
How many calling minutes are needed for a monthly cost of at least $7?
This can be solved by the following inequality:
For a monthly cost of at least $7, you need to have at least 100 calling minutes.
How many calling minutes are needed for a monthly cost of at most 8:
For a monthly cost of at most $8, you need to have at most 110 calling minutes.
For a monthly cost of at least $7 and at most $8, you can have between 100 and 110 calling minutes.
Answer:
a= 18 girls in the class, b= 20 boys and 15 girls, 12 oranges better price.
Step-by-step explanation:
for question a, there are 18 girls in the class, this is how i worked it out:
the ratio of boys to girls is 4:3.
there are 24 boys.
24 is 6 times more than 4.
if boys are 6 times more than the original ratio, we also have to times the amount of girls by 6.
6x3= 18.
for question b i got 20 boys and 15 girls, this is how i did it.
there are 35 students in total.
4:3= boys to girls.
4+3=7
7 goes into 35 five times.
ratio of boys to girls is 4:3 so 5x4 for boys = 20 and 3x5 for girls = 15.
answer= 20 boys and 15 girls.
12 oranges is a better deal, this is how i worked it out.
it is 60 for 12 oranges.
it is 48 for 8 oranges.
12x5= 60 , 8x6=48.
you only have to times 12 by 5 to get it to the price but you have to times 8 by 6 to get it to the price, proving that 12 oranges for 60 is a better deal.
Answer:
A unit rate is a rate where the second quantity is one unit , such as $34 per pound, 25 miles per hour, 15 Indian Rupees per Brazilian Real, etc.
Step-by-step explanation:
how do you not know what are unit rates
9x^3-39x^2-38x+40=(3x-2)(3x+4)(x-5) by synthetic division
Thus roots are -4/3, 2/3, 5
Answer: 
Step-by-step explanation:
First, we divide the composite figure into two distinct geometric shapes. This would be a triangle and a square. To find the triangle we use the formula:
A = 1/2bh
To find the base of the triangle we can add:
9 + 9 + 18 = 36
Now we plug in and solve:
A = 1/2bh
A = 1/2(36)(27)
= 1/2(972)
= 486
To find the square, we can use length x width:
18×18 = 324
Now, we add the sums together:
486 + 324 = 810
