Problem 2:

What is the value of [tex]\sqrt[3]{2 a^2 b^4} + \frac{a-c}{(b+c)^2}[/tex] if [tex]a = 4[/tex], [tex]b = 2[/tex], and [tex]c = -5[/tex]?

A. [tex]16\sqrt{2} - 3[/tex]



Answer :

Let's solve the problem step by step. We need to find the value of [tex]\(\sqrt[3]{2 a^2 b^4} + \frac{a-c}{(b+c)^2}\)[/tex] given that [tex]\(a = 4\)[/tex], [tex]\(b = 2\)[/tex], and [tex]\(c = -5\)[/tex].

### Step 1: Simplify the first term [tex]\(\sqrt[3]{2 a^2 b^4}\)[/tex]
Substitute the given values for [tex]\(a\)[/tex] and [tex]\(b\)[/tex]:

[tex]\[ \sqrt[3]{2 \cdot (4)^2 \cdot (2)^4} = \sqrt[3]{2 \cdot 16 \cdot 16} = \sqrt[3]{2 \cdot 256} \][/tex]

First, multiply [tex]\(2\)[/tex] by [tex]\(256\)[/tex]:

[tex]\[ 2 \cdot 256 = 512 \][/tex]

Next, take the cube root of [tex]\(512\)[/tex]:

[tex]\[ \sqrt[3]{512} = 8 \][/tex]

So, the value of the first term is:

[tex]\[ \sqrt[3]{2 a^2 b^4} = 8 \][/tex]

### Step 2: Simplify the second term [tex]\(\frac{a-c}{(b+c)^2}\)[/tex]
Substitute the given values for [tex]\(a\)[/tex], [tex]\(b\)[/tex], and [tex]\(c\)[/tex]:

[tex]\[ \frac{4 - (-5)}{(2 + (-5))^2} = \frac{4 + 5}{(2 - 5)^2} = \frac{9}{(-3)^2} = \frac{9}{9} \][/tex]

Simplify the expression:

[tex]\[ \frac{9}{9} = 1 \][/tex]

So, the value of the second term is:

[tex]\[ \frac{a-c}{(b+c)^2} = 1 \][/tex]

### Step 3: Add the simplified terms together
Add the two results obtained from steps 1 and 2:

[tex]\[ 8 + 1 = 9 \][/tex]

Thus, the value of the expression [tex]\(\sqrt[3]{2 a^2 b^4} + \frac{a-c}{(b+c)^2}\)[/tex] is:

[tex]\[ 9 \][/tex]