Let's solve each part of the problem step by step.
1. Solve \( -3 + 9 \)
This is a simple addition problem involving integers:
\[
-3 + 9 = 6
\]
2. Solve \( -93.1 \div 24.5 \)
This is a division problem involving decimals. To simplify the calculation, we can eliminate the decimals by multiplying both the numerator and the denominator by 10:
\[
-93.1 \div 24.5 = \frac{-93.1}{24.5} = \frac{-931}{245}
\]
Now, perform the division:
\[
-931 \div 245 = -3.8
\]
So,
\[
-93.1 \div 24.5 = -3.8
\]
3. Solve \( \frac{2}{5} \times \frac{-7}{8} \)
This is a multiplication problem involving fractions. To multiply fractions, multiply the numerators together and the denominators together:
\[
\frac{2}{5} \times \frac{-7}{8} = \frac{2 \times (-7)}{5 \times 8} = \frac{-14}{40}
\]
Simplify the fraction by dividing the numerator and the denominator by their greatest common divisor, which is 2:
\[
\frac{-14}{40} = \frac{-7}{20}
\]
So,
\[
\frac{2}{5} \times \frac{-7}{8} = -\frac{7}{20}
\]
Final Answers
Combining all the solutions, we have:
\[
-3 + 9 = 6
\]
\[
-93.1 \div 24.5 = -3.8
\]
\[
\frac{2}{5} \times \frac{-7}{8} = -\frac{7}{20}
\]
The final answers are:
\[
\boxed{6, -3.8, -\frac{7}{20}}
\]
Parent Tip: Review the logic above to help your child master the concept of 7th grade math.
