In your own words describe the process for adding decimals PLS HELP THIS AFFECTS MY GRADE ALOT

in order to find the answer, when adding decimals, you must count the numbers before the decimal points. Then, remove the decimal point and proceed as you would would adding whole numbers. Once finished, start from the side that has the first number and count up to the amount of numbers you counted before. Then, place the decimal point and simplify if needed.

Step-by-step explanation:

don't know if you want to answer in these exact words but it's a start by making sure you are familiar with the concept

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240