Answer:
9) 7sqrt(2)
11) 8sqrt(2)
13) 3sqrt(7)
Explanation:
9) factor the radicand 98 into 7*7*2, 7^2*2, and then factor out the 7 squared to the outside of the radical to get 7 square roots of 2
11) factor the radicand 128 into 8*8*2, 8^2*2, and then factor out the 8 squared to the outside of the radical to get 8 square roots of 2
13) factor the radicand 63 into 3*3*7, 3^2*2, then factor out the 3 squared outside of the radical to get 3 square roots of 7