Step-by-step explanation:
2x + 7x - 10 = 180° because these rwo angles are supplementary
10x - 10 = 180°
10x = 190° divide both sides by 10
x = 19
measure of angle on the right:
8x - 10 ➡ 8 × 19 - 10 = 142°
measure of angle on the left:
2x ➡ 2 × 19 = 38°
Answer:
There were 120 questions on the test.
Step-by-step explanation:
It is given that:
Number of questions answered = 54
Grade percent = 45%
Let,
x be the total number of questions
45% of x = 54
Dividing both sides by 0.45
Therefore,
There were 120 questions on the test.
14/17 is .82 while 31/39 is .79