The average of two students' scores on a math exam is 70. The firs student's score is ten less than twice the score of the second student. What is the score of the first student on the exam? A: 90.
Why is this?

Question

The average of two students' scores on a math exam is 70. The firs student's score is ten less than twice the score of the second student. What is the score of the first student on the exam? A: 90.
Why is this?

4n1m0s1ty · Answer

Do you know the formula for the average?

anonymous · Answer

my false logic:
2y-10=70
2y=80
y=40
80-10=70

anonymous · Answer

the sum of the scores dived by the amount of scores. yes

anonymous · Answer

divided*

4n1m0s1ty · Answer

So lets call student 1's score x and student 2's score y. Can you use this to write an algebraic expression?

anonymous · Answer

thank you waterineyes :)

anonymous · Answer

Welcome dear..

anonymous · Answer

I have done a little mistake:

x = 2y - 10

$$\frac{x + y}{2} = 70 \implies \frac{3y-10}{2} \implies 3y - 10 = 140 \implies 3y = 150$$

Now find y from it and then find x..

anonymous · Answer

oh my... thank you for that. i appreciate that D:

anonymous · Answer

Welcome dear and sorry...

anonymous · Answer

oh dont be at all! im just glad im getting help on all these questions D: math is probably my worst subject haha