Question

Amy and Stephanie were playing a number game. Abby picked a number and told Stephanie that if she added seven to the number and multiplied the result by four, it would equal eight. Which equation could Stephanie use to find the number x?

1) 4x + 7 = 8
2) 4(x + 7) = 8
3) 4x - 7 = 8
4) 4(x - 7) = 8

Answer 1

Stephanie should use the equation 4(x + 7) = 8 to find the number x, as this equation correctly represents adding seven to x and then multiplying the result by four to equal eight.

Step-by-step explanation:

Amy and Stephanie were playing a number game where Amy picked a number and told Stephanie that if she added seven to the number and multiplied the result by four, it would equal eight. Stephanie could use the equation 4(x + 7) = 8 to find the number x. This is because, according to the order of operations, Stephanie needs to add seven to the number Amy picked and then multiply the sum by four. Following the rules of mathematics on multiplying numbers:

• When two positive numbers multiply, the result is positive.
• When two negative numbers multiply, the result is also positive.
• When a positive and a negative number are multiplied, the result is negative.

This is relevant because it explains why the equation must be structured to multiply the entire sum by four. Therefore, the correct choice is option 2: 4(x + 7) = 8.