1. a)rad3(x-y)=rad3×rad12=rad3×2rad3=6
b)6x²-5x²=x²
c)7×(-1)²-5×(-1)+15=7+5+15=27
2. a)(3rad5)²-2²=45-4=41
b)(3x-5y)(3x+5y)
c)F