3. Mr. Mele has been buying many plaid shirts recently. The linear equation used to model the amount of money in his bank account (y) based on the number of shirts bought, x, is y=-45x + 700. What is the rate of change and what does it represent? (a) The rate of change is $700 and it represents the initial amount in his account.

(b) The rate of change is - 45 and it represents the cost of each shirt.

(c) The rate of change is - 45 and it represents the amount his bank account goes down per • shirt he buys.

(d) The rate of change is - 45 and it represents the amount of money in his bank account

f

step-by-step explanation:

f

853.3

step-by-step explanation:

the first one

step-by-step explanation:

just id the test.

hello!

to begin with, we're given that on earth, a rock weighs 20 pounds, and while on jupiter, that same rock weighs 42 pounds. now, we're trying to find the weight of a rock that weighs 10.5 pounds on earth, on jupiter.

to solve this, first, set up a proportion, cross-multiply, and solve it algebraically.

setting up the proportion is the hardest and the most confusing part of the problem, but it's simple.

if on earth, the rock weighs 20 lbs, and on jupiter it weighs 42 lbs, our first part of our proportion is 20/42 lbs. the second part has to be equal to each other. this means that 10.5 has to be on the numerator of the fraction, and x, the value we're trying to find, has to be on the denominator. remember that the rock weighs 10.5 lbs on earth, and we're trying to find the weight of it on jupiter (which is x).

20/42 = 10.5/x

next, you would cross-multiply.

20x = 42(10.5)

20x = 441

now, solve it algebraically by using division.

x = 22.05 lbs

this can be rounded to 22.1 lbs.

therefore, the weight of the rock on jupiter is 22.1 lbs, the fourth choice.