[tex]3\sqrt[]{2y^3}.7\sqrt[]{18y}[/tex]
We will start with 3 x 7 = 21
[tex]\sqrt[]{2y^3}\times\sqrt[]{18y}=\sqrt[]{2y^3\times18y}[/tex]
Multiply the values under the root
[tex]\sqrt[]{(2\times18)(y^3\times y)}=\sqrt[]{36y^4}[/tex]
Square root 36 = 6 and square root y^4 = y^2
[tex]\sqrt[]{36y^4}=6y^2[/tex]
Then multiply 21 by 6y^2
[tex]21\times6y^2=126y^2[/tex]
The answer is D
