4(2x-5)+7(x+2)
bracket means multiplying
do 4(2x+5) first
4*2x=8x
4*-5=-20
7*x=7x
7*2=14
8x-20+7x+14
do the x first
8x+7x=15x
-20+14=-6
answers: 15x-6 or -6+15x
Answer:
Step-by-step explanation:
Let's first find the exponential function that models the situation in year one. The exponential standard form is
where a is the initial value and b is the growth/decay rate in decimal form. If it is growth it is added to 100% of the initial value; if it is decay it is taken away from 100% of the initial value. We are told that the number of cars in year one was 80 million, so
a = 80 (in millions)
If b is increasing by 10%, then we are adding that amount to the initial 100% we started with to give us 100% + 10% = 110% or, in decimal form, 1.1
The model for our situation is
where y is the number of cars after x years goes by. We want to find the difference between years 3 and 2, so we will use our model twice, replacing x with both a 2 and then a 3 and subtracting.
When x = 2:
and
y = 80(1.21) so
y = 96.8 million cars
When x = 3:
and
y = 80(1.331) so
y = 106.48 million cars
The difference between years 3 and 2 is
106.48 - 96.8 = 9.68 million cars
I just realized I forgot a whole unit we did this year, but a(n)=5n-12
is the explicit form if that helps at all
Answer:
Step-by-step explanation:
In this scenario, Octavia should buy at least 12 small milkshakes. At $2.50 each small milkshake, buying 12 would be a total of $30. Since she needs to buy atleast 20 total milkshakes, she would need to buy 8 large milkshakes which at $6 each would cost her a total of $48. Together this would sum up to be $78 for the 20 milkshakes which would mean that Octavia is still under her budget.
