1) squareroot of 45 = squareroot (9 x 5)
9 has a squareroot, so you can take that out from under the squareroot sign
and you get -3(squareroot 5)
2) same thing squareroot 180 = squareroot( 36 x 5) 36 has a squareroot, so you get
6(squareroot 5)
3) squareroot 8x^2y = squareroot (4 times 2 times x^2y) 4 and x^2 have squareroots, so you get
2x(squareroot 2y)