Solve the equation a. 0.76, –0.76 c. 3.87 b. 4.98 d. 1.53, –1.53 Please select the best answer from the choices provided A B C D

You didn't write the equation you like to be solved. It is clear though, from the options you gave, that there are two equations you want to be solved simultaneously. I will give an example to illustrate this, and you may apply the process in solving your problem.

Step-by-step explanation:

Let

x + y = 7 (1)

x - 2y = -2(2)

SOLVING USING THE SUBSTITUTION METHOD.

From (1), make y the subject.

y = 7 - x (3)

Substitute the value of y in (3) into (2)

x - 2(7 - x) = -2

x - 14 + 2x = -2

x + 2x = -2 + 14

3x = 12

Divide both sides by 3

x = 12/3 = 4

Now use x = 4 in (3)

y = 7 - 4 = 3

Therefore, ( x, y) = (4, 3)

SOLVING USING THE ELIMINATION METHOD.

x + y = 7 (1)

x - 2y = -2(2)

First, let us eliminate x by subtracting (2) from (1)

(x + y) - (x - 2y) = 7 - (-2)

y + 2y = 7 + 2

3y = 9

Divide both sides by 3

y = 9/3 = 3

To eliminate y, first multiply (1) by 2, and add the result to (1)

2 × (1): 2x + 2y = 14 (3)

x - 2y = -2(2)

3x = 12

x = 12/3 = 4

Therefore (x, y) = (4, 3)

(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

just keep asking questions until you have a better understanding.

step-by-step explanation: