Can anyone solve these and show work? please help a girl out lol

17) 45-45-90 triangle so
45 | 45 | 90
n | n | n root 2
15 | x

n=n=x=15 u

y is hypotenuse, since 15 is n, hypotenuse is gonna be n root 2 so 15 root 2

18) 30-60-90 triangle

30 | 60 | 90
n | n root 3 | 2n
x | y | 15

2n=15
n=7.5=x
7.5 root 3=y

Yeah she/ he needs look how long that is man

Planet earth has a mass of 5.9726x10²⁴ kg.then: 5.9726x10²⁴ kg=100% of the total earth mass.if the water´s mass=5x10-4 % of the total mass, we can solve this problem by the rule of three.5.9726x10²⁴ %*10⁻⁴ %x=(5.9726x10²³ kg)(5*10⁻⁴  %) / 100 %=2.9863x10¹⁹ kganswer:   the mass of the planet´s water would be   2.9863 x 10¹⁹ kg.