( 15n2 - 5n + 45 ) ÷ 5​

I'm assuming we need to simplify this expression. (Tip when you are writing n squared, please write n^2, not n2.)

Since we can see that there is a 5 in each term inside the ( ), we simplify have to remove that if the whole thing is going to be divided by 5.

(15n^2-5n+45)/5

=3n^2-n+9

3n^2-n+9

Step-by-step explanation:

You would want to divide the 5 between each of the terms. 15n^2 ÷ 5 is 3n^2. 15 ÷ 5 is 3. The n^2 stays, so 3n^2. -5 ÷ 5 is -1. We don't have to worry about writing the -1. Rather, just write the -n, it is the same as writing -1n. Lastly, 45 ÷ 5 is 9. You have to put the terms together in standard form. Standard form is just writing the numbers from greatest power to least power. The 3n^2 would come first since 2 is the greatest power. Next would be the -n, and lastly the 9. The 9 is the constant, which always comes last. A constant would be a number without a variable after it, like 2x is not a constant but just 2 is. Therefore, the answer is 3n^2-n+9.

-4

step-by-step explanation:

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.