Question

Lila wants to earn an average grade of 85 across all seven tests in her Algebra course. So far, she has taken six tests, and her scores are as follows: 78, 92, 87, 80, 84, and 88. Write an equation to represent the situation and solve it to find the grade she needs to earn on the seventh test to reach her goal of an average of 85
509x/7 =85

78+92+87+80+84+88+x/7 = 85

78+92+87+80+84+88/7 +x= 85

78+92+87+80+84+88/ 6 +x = 85
Answer
Write an equation to represent the situation?
Answer
Write an equation to represent the situation
Answered by GPT-4o mini
To find the grade Lila needs on her seventh test to achieve an average of 85 across all seven tests, let's set up the equation step by step.

1. **Calculate the total score needed for an average of 85 over 7 tests**:
\[
\text{Total score} = \text{desired average} \times \text{number of tests} = 85 \times 7 = 595
\]

2. **Sum the scores of the six tests she's already taken**:
\[
78 + 92 + 87 + 80 + 84 + 88 = 509
\]

3. **Let \( x \) be the score she needs on the seventh test**. We can then set up the equation based on the total score:
\[
509 + x = 595
\]

4. **Now solve for \( x \)**:
\[
x = 595 - 509
\]
\[
x = 86
\]

So, Lila needs to score **86** on her seventh test to achieve her goal of an average grade of 85 across all seven tests.