12. at the beginning of the day, the stock market goes up 30\\frac{1}{2} points. at the end of the day, the…

12. at the beginning of the day, the stock market goes up 30\\frac{1}{2} points. at the end of the day, the stock market goes down 120\\frac{1}{4} points. what is the total change in the stock market from the beginning of the day to the end of the day?
Answer
Explanation:
Step1: Convert mixed - numbers to improper fractions
$30\frac{1}{2}=\frac{30\times2 + 1}{2}=\frac{61}{2}$ and $120\frac{1}{4}=\frac{120\times4+1}{4}=\frac{481}{4}$
Step2: Find the net change
The change is the initial increase minus the final decrease. First, make the common denominator for the two fractions. The common denominator of 2 and 4 is 4. So $\frac{61}{2}=\frac{61\times2}{2\times2}=\frac{122}{4}$. The net change is $\frac{122}{4}-\frac{481}{4}=\frac{122 - 481}{4}=\frac{- 359}{4}=-89\frac{3}{4}$
Answer:
$-89\frac{3}{4}$ points