- 20y - 7x = -14
10y - 2x = -4

(2, 0)

General Formulas and Concepts:

Pre-Algebra

Algebra I

Step-by-step explanation:

Step 1: Define systems

-20y - 7x = -14

10y - 2x = -4

Step 2: Rewrite systems

10y - 2x = -4

Step 3: Redefine systems

-20y - 7x = -14

x = 5y + 2

Step 4: Solve for y

Substitution

Step 5: Solve for x

Step 6: Graph systems

Check solution set and systems.

the answers are in the images, i received 100% on this assignment. hope this !

(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