Answer:
[tex] - 40 \sqrt{x} [/tex]
Step-by-step explanation:
We want to simplify:
[tex] \sqrt{5} \times - 4 \sqrt{20x} [/tex]
We rewrite the radicand using prime factorization:
[tex] \sqrt{5} \times - 4 \sqrt{4 \times 5x} [/tex]
This gives us
[tex]\sqrt{5} \times - 4 \sqrt{4} \times \sqrt{5} \times \sqrt{x} [/tex]
Create perfect squares and simplify:
[tex](\sqrt{5} )^{2} \times - 4 \sqrt{4} \times \sqrt{x} [/tex]
[tex]5 \times - 4(2) \sqrt{x} [/tex]
[tex]5 \times - 8 \sqrt{x} = - 40 \sqrt{x} [/tex]