Find the given value of x 2x + 3 for x = 3

First, you need to substitute the value of x in all of the x spots. 
2x+3
2(3)+3.   Us PEMDAS to solve the problem.
6+3
9

If your asking how much altogether for 12 performance the answer will be 98,496.

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.