How do we Round with any numbers, (on a number line) ?

round it to the nearest 10th?

Step-by-step explanation:

that's what I do at least.

Round up or down.

Step-by-step explanation: When you round up, look at the number to the right of the number you wanna round. If it’s less than 5, you round down, if it’s more than 5, you round up. On a number line, for ex. Let’s say you wanna round 550 to hundreds, 600 or 500, 600 would be the answer because 550 is more closer to 600 by default.

Simplifying
9(3c + -1) = 27(3c + -1)

Reorder the terms:
9(-1 + 3c) = 27(3c + -1)
(-1 * 9 + 3c * 9) = 27(3c + -1)
(-9 + 27c) = 27(3c + -1)

Reorder the terms:
-9 + 27c = 27(-1 + 3c)
-9 + 27c = (-1 * 27 + 3c * 27)
-9 + 27c = (-27 + 81c)

Solving
-9 + 27c = -27 + 81c

Solving for variable 'c'.

Move all terms containing c to the left, all other terms to the right.

Add '-81c' to each side of the equation.
-9 + 27c + -81c = -27 + 81c + -81c

Combine like terms: 27c + -81c = -54c
-9 + -54c = -27 + 81c + -81c

Combine like terms: 81c + -81c = 0
-9 + -54c = -27 + 0
-9 + -54c = -27

Add '9' to each side of the equation.
-9 + 9 + -54c = -27 + 9

Combine like terms: -9 + 9 = 0
0 + -54c = -27 + 9
-54c = -27 + 9

Combine like terms: -27 + 9 = -18
-54c = -18

Divide each side by '-54'.
c = 0.3333333333

Simplifying
c = 0.3333333333