Question

1. find the sum: $(-15)+(-9)$

1. find the sum: $32+(-42)$

1. find the difference: $7.2-(-2.2)$

1. find the product: $(-24)(-0.2)$

1. find the product: $45\times(-4)$

Explanation:

Problem 6:

Step1: Add two negative numbers

When adding two negative numbers, we add their absolute values and keep the negative sign. So, $|-15| = 15$ and $|-9| = 9$. Then we add these absolute values: $15 + 9 = 24$. Since both numbers are negative, the sum is negative.
$$(-15) + (-9) = - (15 + 9) = -24$$

Step1: Add a positive and a negative number

To add a positive and a negative number, we subtract the smaller absolute value from the larger absolute value and take the sign of the number with the larger absolute value. Here, $|32| = 32$ and $|-42| = 42$. Since $42 > 32$, we subtract: $42 - 32 = 10$. The number with the larger absolute value is -42 (negative), so the sum is negative.
$$32 + (-42) = - (42 - 32) = -10$$

Step1: Subtract a negative number

Subtracting a negative number is the same as adding its positive counterpart. So, $7.2 - (-2.2)$ is equivalent to $7.2 + 2.2$.
$$7.2 - (-2.2) = 7.2 + 2.2 = 9.4$$

Answer:

-24

Problem 7: