Answer:
score = 63
Step-by-step explanation:
1. To write the proportion take the score of the test over the number of points and set it equal to the percent over 100
score 90
----------- = -----------
70 100
Using cross products
100 * score = 90*70
100 score = 6300
Divide by 100
100/100 * score = 6300/100
6x - 12 + x = 9
6x + x - 12 = 9
Collect like terms
7x - 12 = 9
Add both sides 12
7x - 12 + 12 = 9 + 12
7x = 21
Divide both sides by 7
7x ÷ 7 = 21 ÷ 7
x = 3
only I think 10 failed all courses
