A coffee shop owner blends a gourmet brand of coffee with a cheaper brand. The gourmet coffee usually sells for $9.00 per pound. The cheaper brand sells for $7.00 per pound. How much of each type should be mixed in order to have 50 pounds of coffee that is worth $7.50 per pound?

Here is my answer, i'm sorry if you didn't understand my explanation

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.

12x+8-x=12x-x+8=11x+8=11

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