Crane took 2 math test. His average score on the 2 test was 85. Then he took a third test and scored 9 points on it. Write an expression for his average score for all 3 test.

Average = 59.6667

Step-by-step explanation:

If Crane's average score on the first 2 tests was 85, we know that the sum of these both tests' score is 85 * 2 = 170.

Now, we sum the score of the third test, which is 9, so we have now 3 tests, and the sum of the scores is 170 + 9 = 179.

Calculating the new average, we divide the sum of the scores by 3, because now we have 3 tests instead of 2, so:

Average = 179 / 3 = 59.6667