Question

Sara follows these two steps to prepare a roast:

1. Preheat the oven for 10 minutes.
2. Place roast in oven and cook for 20 minutes per pound.
Last week, it took a total of 90 minutes for Sara to prepare a roast.
Part A
Write an equation that can be used to determine the weight, in pounds, of the roast Sara prepared. Be sure to define the variable in your
equation
Define the variable
Equation

Answer 1

Let the no of lbs be p

The equation is

• 20p+10=90

On solving

• 20p=80
• p=4lbs

Answer 2

• 20x + 10 = 90
• 4 pounds

Explanation:

Let the number of pounds is x.

Consider the time for preheat and set the equation:

• 20x + 10 = 90

Solve for x to find the weight:

• 20x = 90 - 10
• 20x = 80
• x = 80/20
• x = 4