Show that

[tex]\[
\frac{0.85 \times 0.85 \times 0.85 + 0.15 \times 0.15 \times 0.15}{0.85 \times 0.85 \times 0.85 + 0.15 \times 0.15} = 1
\][/tex]



Answer :

Let’s break down the given expression step-by-step to show why the given result is:

[tex]\[ \frac{0.85 \cdot 0.85 \cdot 0.85 + 0.15 \cdot 0.15 \cdot 0.15}{0.85 \cdot 0.85 \cdot (-0.85) \cdot 0.15 + 0.15 \cdot 0.15} \][/tex]

First, we will evaluate the numerator:

1. Calculate [tex]\(0.85 \cdot 0.85 \cdot 0.85\)[/tex]:
[tex]\[ 0.85^3 = 0.614125 \][/tex]

2. Calculate [tex]\(0.15 \cdot 0.15 \cdot 0.15\)[/tex]:
[tex]\[ 0.15^3 = 0.003375 \][/tex]

3. Add these two results:
[tex]\[ 0.614125 + 0.003375 = 0.6175 \][/tex]

So, the numerator is [tex]\(0.6175\)[/tex].

Next, let’s evaluate the denominator:

1. Calculate [tex]\(0.85 \cdot 0.85\)[/tex]:
[tex]\[ 0.85^2 = 0.7225 \][/tex]

2. Multiply this by [tex]\(-0.85\)[/tex] and by [tex]\(0.15\)[/tex]:
[tex]\[ 0.7225 \cdot (-0.85) \cdot 0.15 = 0.7225 \cdot -0.1275 = -0.09219375 \][/tex]

3. Calculate [tex]\(0.15 \cdot 0.15\)[/tex]:
[tex]\[ 0.15^2 = 0.0225 \][/tex]

4. Add these two results:
[tex]\[ -0.09219375 + 0.0225 = -0.06969375 \][/tex]

So, the denominator is approximately [tex]\(-0.06969375\)[/tex].

Finally, we evaluate the fraction by dividing the numerator by the denominator:

[tex]\[ \frac{0.6175}{-0.06969375} \approx -8.869736960229824 \][/tex]

Therefore, the overall result of this expression is [tex]\(\boxed{-8.869736960229824}\)[/tex].