Let's work through these two problems step by step.
1. First Problem: [tex]\(-9 \times (-4)\)[/tex]
- When multiplying two numbers, we need to consider both their magnitudes and their signs.
- The magnitude of [tex]\( -9 \)[/tex] is [tex]\( 9 \)[/tex] and the magnitude of [tex]\( -4 \)[/tex] is [tex]\( 4 \)[/tex].
- When you multiply two negative numbers, the result is positive because a negative times a negative is a positive.
- Therefore, [tex]\( -9 \times (-4) = 36 \)[/tex].
2. Second Problem: [tex]\( 21 \div (-7) \)[/tex]
- Division, like multiplication, also considers the magnitude and signs of numbers.
- The magnitude of [tex]\( 21 \)[/tex] is [tex]\( 21 \)[/tex], and the magnitude of [tex]\( -7 \)[/tex] is [tex]\( 7 \)[/tex].
- When you divide a positive number by a negative number, the result is negative because a positive divided by a negative is a negative.
- Therefore, [tex]\( 21 \div (-7) = -3.0 \)[/tex].
Thus, the answers are:
[tex]\[ -9 \times (-4) = 36 \][/tex]
[tex]\[ 21 \div (-7) = -3.0 \][/tex]
