Please help me by the way this is a 2 mark question from mathswatch
1 answer:
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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
Answer: 410 possible points
To solve for the possible points in the course, use a proportion and cross multiply.
<h2>What is a proportion?</h2>
A proportion is two fractions that are equal to each other. For the fractions to be equal, they are proportionate. In our math problem, percentage is proportionate the the number of points.
The fractions represent information you have, and one variable will represent what you are solving for.
<h2 /><h3>Given</h3>Your points = 361
Points to get an 'A' = your points + 8
'A' = 90% of possible points
<h3>Find the points needed for an 'A' at 90%</h3>Points to get an 'A' = your points + 8
= 361 + 8
= 369
<h3>State variables</h3>let <em>x</em> be the amount of possible points
<h3 /><h3>Write a proportion</h3>We know the number of points for 90% is 369 points. Remember that 90% is the same as 90/100.
Keep the information with the same units inside the same fraction. Here, percentage is represented by the first fraction. Points is represented by the second fraction.
We can solve using cross multiplication. This is when we multiply each numerator by the denominator from the other fraction.
Simplify by multiplying.
Isolate the variable <em>x</em>.
Divide both sides by 90 to cancel out 90 on the left.
Divide.
Solved for <em>x</em>, representing the possible points.
∴ The possible points in the art course is 410.
Learn more about finding a missing number given percentage here: brainly.com/question/26535441