b) Work out:
[tex]\[ (10 - 3 \times 2)^2 \][/tex]

c) What is the value of the power [tex]\(a\)[/tex] if [tex]\(5^a = \frac{1}{125}\)[/tex]?



Answer :

Certainly! Let's solve each part step-by-step:

### Part b:
Work out
[tex]\[ (10 - 3 \times 2)^2 \][/tex]

1. Step 1: First, perform the multiplication inside the parentheses:
[tex]\[ 3 \times 2 = 6 \][/tex]
2. Step 2: Substitute this value back into the expression:
[tex]\[ 10 - 6 \][/tex]
3. Step 3: Perform the subtraction:
[tex]\[ 10 - 6 = 4 \][/tex]
4. Step 4: Now, square the result:
[tex]\[ 4^2 = 16 \][/tex]

So, the result for part b is:
[tex]\[ (10 - 3 \times 2)^2 = 16 \][/tex]

### Part c:
Find the value of the power \( a \) if
[tex]\[ 5^a = \frac{1}{125} \][/tex]

1. Step 1: Recognize that \( \frac{1}{125} \) can be written as \( 125^{-1} \).
2. Step 2: Recall that \( 125 \) is \( 5^3 \), so we have:
[tex]\[ \frac{1}{125} = \frac{1}{5^3} = 5^{-3} \][/tex]
3. Step 3: Hence, from the equation \( 5^a = 5^{-3} \), we can equate the exponents:
[tex]\[ a = -3 \][/tex]

So, the value of the power \( a \) is:
[tex]\[ a = -3 \][/tex]

Thus, the complete solution is:

Part b:
[tex]\[ (10 - 3 \times 2)^2 = 16 \][/tex]

Part c:
[tex]\[ a = -3 \text{ for } 5^a = \frac{1}{125} \][/tex]