[tex]$(+7)$[/tex], [tex]$(-9)$[/tex], and [tex]$(-12)$[/tex] are three given integers. Answer the following questions:

a) Compare the sum of [tex]$(+7)$[/tex] and [tex]$(-9)$[/tex] with the difference of [tex]$(-9)$[/tex] and [tex]$(-12)$[/tex].

b) Write a mathematical expression to subtract the sum of [tex]$(+7)$[/tex] and [tex]$(-9)$[/tex] from [tex]$(-12)$[/tex].

c) Simplify the expression and find the result.

(i) Is the result a whole number? Give a reason.



Answer :

Sure, let's go through each part of the question step-by-step.

### a) Compare the sum of [tex]\( (+7) \)[/tex] and [tex]\( (-9) \)[/tex] with the difference of [tex]\( (-9) \)[/tex] and [tex]\( (-12) \)[/tex].

First, calculate the sum of [tex]\( (+7) \)[/tex] and [tex]\( (-9) \)[/tex].

[tex]\[ (+7) + (-9) = 7 - 9 = -2 \][/tex]

Next, calculate the difference of [tex]\( (-9) \)[/tex] and [tex]\( (-12) \)[/tex].

[tex]\[ (-9) - (-12) = -9 + 12 = 3 \][/tex]

Now, compare the two results:
- Sum of [tex]\( (+7) \)[/tex] and [tex]\( (-9) \)[/tex] is [tex]\( -2 \)[/tex]
- Difference of [tex]\( (-9) \)[/tex] and [tex]\( (-12) \)[/tex] is [tex]\( 3 \)[/tex]

So they are not equal. The comparison is [tex]\( -2 \ne 3 \)[/tex].

### b) Write a mathematical expression to subtract the sum of [tex]\( (+7) \)[/tex] and [tex]\( (-9) \)[/tex] from [tex]\( (-12) \)[/tex].

First, write down the sum of [tex]\( (+7) \)[/tex] and [tex]\( (-9) \)[/tex]:

[tex]\[ (+7) + (-9) = -2 \][/tex]

Now, we need to subtract this sum from [tex]\( (-12) \)[/tex]:

[tex]\[ (-12) - \left[(+7) + (-9)\right] \][/tex]

### c) Simplify the expression and find the result.

Using the expression from part b:

[tex]\[ (-12) - \left[(+7) + (-9)\right] \][/tex]

We know from part a that [tex]\( (+7) + (-9) = -2 \)[/tex], so substitute [tex]\( -2 \)[/tex] into the expression:

[tex]\[ (-12) - (-2) = -12 + 2 = -10 \][/tex]

The result is [tex]\( -10 \)[/tex].

### d) (i) Is the result a whole number? Give reason.

Yes, the result [tex]\( -10 \)[/tex] is a whole number. A whole number is any of the numbers {0, 1, 2, 3, ...} and their negative counterparts, including zero. Since [tex]\( -10 \)[/tex] is an integer from the set of whole numbers, it qualifies as a whole number.