Let x be the score Amaya gets on the final test. She wants her average of all 3 tests to be between 80 and 89:
<span>80 ≤ (78 + 91 + x) / 3 ≤ 89 </span>
<span>Multiply everything by 3: </span>
<span>240 ≤ 78 + 91 + x ≤ 267 </span>
<span>240 ≤ 169 + x ≤ 267 </span>
<span>Subtract 169 from everything: </span>
<span>240 - 169 ≤ x ≤ 267 - 169 </span>
<span>71 ≤ x ≤ 98 </span>
<span>Answer: </span>
<span>She needs to score between 71 and 98 to get a B for the course.</span>
Answer:
C.
Step-by-step explanation:
Recall that the sum of the (3) interior angles of a triangle <em>must</em> equate to 180.
In other words:

Where x is our unknown angle. So, we need to solve for x.
On the left, add 55 and 20:

Subtract 75 from both sides. The left side cancels:

Therefore, the third angle is 105 degrees.
Our answer is C.
Answer:
...........the answer is 7?!