please translate

“A student scored five points more on the second quiz than he did the first. He scored eleven points lower on the third quiz than he did the first. If the average of the three quiz scores is 70, what was his score on the first quiz?”

Let x = the score on the first test.

x + x + 5 + x - 11 = 3(70)
3x - 6 = 210
3x = 216
x = ?

x=213

x+72

x=72

To solve this problem, we need to set up an equation based on the given information and then solve it for the unknown variable (the score on the first quiz).

Let's say the score on the first quiz is "x".
According to the problem, the student scored five points more on the second quiz than on the first quiz. So, the score on the second quiz would be "x + 5".
The student also scored eleven points lower on the third quiz than on the first quiz. Therefore, the score on the third quiz would be "x - 11".

To find the average of the three quiz scores, we add up the scores and divide by 3:
(x + x + 5 + x - 11)/3 = 70

Now, we can solve this equation to find the value of "x" (the score on the first quiz).

Combining like terms, we get:
(3x - 6)/3 = 70

Next, we multiply both sides of the equation by 3 to eliminate the fraction:
3x - 6 = 210

Adding 6 to both sides of the equation, we have:
3x = 216

Finally, dividing both sides of the equation by 3, we find:
x = 72

Therefore, the score on the first quiz was 72.