Answer :

To multiply and simplify the expression [tex]\(\sqrt{3}(7 \sqrt{10} + \sqrt{7})\)[/tex], follow these steps:

1. Distribute [tex]\(\sqrt{3}\)[/tex] to each term inside the parentheses:

[tex]\[ \sqrt{3} \cdot 7 \sqrt{10} + \sqrt{3} \cdot \sqrt{7} \][/tex]

2. Multiply [tex]\(\sqrt{3}\)[/tex] with [tex]\(7 \sqrt{10}\)[/tex]:

[tex]\[ 7 \cdot \sqrt{3} \cdot \sqrt{10} \][/tex]

We can use the property of square roots [tex]\(\sqrt{a} \cdot \sqrt{b} = \sqrt{ab}\)[/tex]:

[tex]\[ 7 \cdot \sqrt{3 \cdot 10} = 7 \cdot \sqrt{30} \][/tex]

Numerically, this gives:

[tex]\[ 7 \cdot \sqrt{30} \approx 38.34057902536163 \][/tex]

3. Multiply [tex]\(\sqrt{3}\)[/tex] with [tex]\(\sqrt{7}\)[/tex]:

[tex]\[ \sqrt{3} \cdot \sqrt{7} \][/tex]

Again, using the square root property:

[tex]\[ \sqrt{3 \cdot 7} = \sqrt{21} \][/tex]

Numerically, this gives:

[tex]\[ \sqrt{21} \approx 4.58257569495584 \][/tex]

4. Add the results from steps 2 and 3:

[tex]\[ 7 \sqrt{30} + \sqrt{21} \][/tex]

Numerically, adding these two results:

[tex]\[ 38.34057902536163 + 4.58257569495584 = 42.92315472031747 \][/tex]

Hence, the simplified expression is approximately:

[tex]\[ \boxed{42.92315472031747} \][/tex]