Me ! what does the line mean under the < thing. what does it mean if the dot is all black vs./2 not filled also my question mark isn't working if that makes it less confusing

The line under means equal too... on this example it means less than or equal to.  It mean you will include the 3.  If there is not a line it means you would not include the 3.

The open circle and closed circle in the graph means:

open circle means: less than or greater than

closed circle means: less than or equal to greater than or equal to.

The line under the < thing is called "less or equals to". So if the dot is black, it means that it is less of equals to the certain number. If there is no line under <, it means that the number is less than the number.

It said that x is less or equals to 3 so the arrow on the line should head towards the left. The dot on the line should be a black dot since x ≤ 3. So your answer should be the third number line.

2 1/2 feet

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.