Using a calculator, you should find that
-2 & 4/5 = -(2 + 4/5) = -(2+0.8) = -2.8
-31/5 = -6.2
So the unknown number is between -6.2 and -2.8
<h3>Possible whole number answers could be: -6, -5, -4, -3, or -2</h3>
If your teacher allows decimal answers, then there are infinitely many possible ways to answer.
1.5 hours=60+30=90 minutes
30 pages : 90 minutes = 0.3 pages/minute
The answer for this problem is39906
640 minus 400 equals 240 being the profit, if that's what you were asking