Question

Using the equation y = 2x + 5 , what would the input need to be for an output of -45?

a. -20

b. -25

c. -85

d. -95

Answer 1

-25

Explanation:

Essentially, y is your output and x is your input.

Here's your base equation: y = 2x + 5

Knowing the information above, let's plug it in:

-45 = 2x + 5

(Subtract 5 from both sides)

-50 = 2x

(Divide both sides by 2 to isolate x)

-25 = x

And there you go.

Answer 2

input is -25

Explanation:

y = 2x + 5

The output is -45 which is y

-45 = 2x + 5

Subtract 5 from each side

-45-5 = 2x

-50 = 2x

Divide each side by 2

-50/2 = 2x/2

-25 = x