Answer:
50
Step-by-step explanation:
Answer:
Step-by-step explanation:
4.5x=90
x=20 history
28 chemistry
42 math
They add to 90.
History test=x
Chemistry test=1.4x
Math test=(1.5)(1.4)=2.1x
They add to 90
First subtract 12 from both sides, then subtract 2x from both sides, multiply both sides by -1, then divide by 4.
x > 3.5
10 hours seems like the most reliable answer because it matches up the best