simplify radical expressions?

Question

1. sqrt[18] + sqrt[300] - sqrt[243]
2. sqrt[25y^2z] +sqrt[16y^2z]
3. 4thrt[48]
4. sqrt[x^2+10x+25]

Answer 1

= 3sqrt(2) +10sqrt(3) - 9sqrt(3) = 3sqrt(2)+sqrt(3)

=5ysqrt(z) +4ysqrt(z) = 9ysqrt(z)

= 2*4thrt(3)

= +/- (x+5)