I feel like i’m wrong lol, Correct me please.

The way you can figure out if a line is parallel, same line or perpendicular. Convert the systems of equation into slope intercept form. Here we have 3x+y=5. Subtract 3x. Y=-3x+5. Now let’s find the second system. 6x+2y=10. Now subtract 6x. 2y=-6x+10. Since we have 2y divide by 2 on both side. -6x/2=3. 10/2=5. Y=-3x+5. We can see the two Systems of equation gives us the same equation. Therefore the system has infinitely many solution or the same line.

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.