9. Verify the following:

(a) [tex]$18 \times [7 + (-3)] = [18 \times 7] + [18 \times (-3)]$[/tex]

(b) [tex]$(-21) \times [(-4) + (-6)] = [(-21) \times (-4)] + [(-21) \times (-6)]$[/tex]

10. A cement company earns a profit of Rs 8 per bag of white cement. How much profit does it make if it sells 100 bags?



Answer :

Let's verify each part of question 9 step-by-step.

### Part (a)

We need to verify the following equation:

[tex]\[ 18 \times [7 + (-3)] = [18 \times 7] + [18 \times (-3)] \][/tex]

1. Calculate the left side:

[tex]\[ 18 \times [7 + (-3)] \][/tex]

First, perform the addition inside the brackets:

[tex]\[ 7 + (-3) = 4 \][/tex]

Then, multiply by 18:

[tex]\[ 18 \times 4 = 72 \][/tex]

2. Calculate the right side:

[tex]\[ [18 \times 7] + [18 \times (-3)] \][/tex]

First, perform the multiplications individually:

[tex]\[ 18 \times 7 = 126 \][/tex]

[tex]\[ 18 \times (-3) = -54 \][/tex]

Then, add the results:

[tex]\[ 126 + (-54) = 72 \][/tex]

3. Compare both sides:

The left side is 72, and the right side is 72. Since both sides are equal, the equation is verified:

[tex]\[ 18 \times [7 + (-3)] = [18 \times 7] + [18 \times (-3)] \][/tex]

### Part (b)

We need to verify the following equation:

[tex]\[ (-21) \times [(-4) + (-6)] = [(-21) \times (-4)] + [(-21) \times (-6)] \][/tex]

1. Calculate the left side:

[tex]\[ (-21) \times [(-4) + (-6)] \][/tex]

First, perform the addition inside the brackets:

[tex]\[ (-4) + (-6) = -10 \][/tex]

Then, multiply by -21:

[tex]\[ (-21) \times (-10) = 210 \][/tex]

2. Calculate the right side:

[tex]\[ [(-21) \times (-4)] + [(-21) \times (-6)] \][/tex]

First, perform the multiplications individually:

[tex]\[ (-21) \times (-4) = 84 \][/tex]

[tex]\[ (-21) \times (-6) = 126 \][/tex]

Then, add the results:

[tex]\[ 84 + 126 = 210 \][/tex]

3. Compare both sides:

The left side is 210, and the right side is 210. Since both sides are equal, the equation is verified:

[tex]\[ (-21) \times [(-4) + (-6)] = [(-21) \times (-4)] + [(-21) \times (-6)] \][/tex]

### Part 10

Unfortunately, the question seems incomplete as it only states "A cement company earns a profit of Rs 8 per bag of white" and does not ask for anything specific. Please provide the rest of the question or clarify what needs to be answered in Part 10.