ANSWER
[tex]\text{12}\sqrt[]{10}[/tex]EXPLANATION
We want to find the simplest radical form of 4√90.
To do this, we have to reduce the number in the square root in factor form and then reduce it with the square root.
We have:
[tex]\begin{gathered} 4\sqrt[]{90} \\ \Rightarrow\text{ 4 }\cdot\text{ }\sqrt[]{\text{9 }\cdot\text{ 10}}\text{ = 4 }\cdot\text{ }\sqrt[]{3\cdot\text{ 3 }\cdot\text{ 10}} \\ \Rightarrow\text{ 4 }\cdot\text{ 3 }\cdot\text{ }\sqrt[]{10} \\ \Rightarrow\text{ 12}\sqrt[]{10} \end{gathered}[/tex]That is the simplest radical form.
