# Video: Evaluating a Variable in a Given Linear Equation given the Values of Other Variables

The profit equation for a small business selling π₯ of item A and π¦ of item B is π = 3π₯ + 4π¦. Find π¦ when π = \$453 and π₯ = \$75.

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### Video Transcript

The profit equation for a small business selling π₯ of item A and π¦ of item B is π is equal to three π₯ plus four π¦. Find π¦ when π is equal to 453 dollars and π₯ equals 75.

We begin this question by considering the equation π is equal to three π₯ plus four π¦. Weβre told that π is equal to 453 dollars. π₯ is equal to 75. So we need to multiply this by three. Our equation becomes 453 is equal to three multiplied by 75 plus four π¦. Three multiplied by 75 is 225. We can then subtract this from both sides of the equation. This gives us four π¦ is equal to 228. Dividing both sides of this equation by four will give us our value for π¦. 228 divided by four is 57. We can therefore conclude that selling 75 of item A and 57 of item B gives a profit of 453 dollars.