Kenneth S. answered • 12/07/16

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Expert Help in Algebra/Trig/(Pre)calculus to Guarantee Success in 2018

x+y = 8

x

^{3}+ y^{3 }= 20 ...this system represents the given statements.Use the factoring rule for sum of cubes:

(x+y)(x

^{2}+xy+y^{2) }= 20. By substituting for the linear factor, you get8(x

^{2}+xy+y^{2}) = 20 or 2(x^{2}+xy+y^{2}) = 5.Now substitute for y; y = 8-x and you will have a (maybe not so nice) quadratic equation in x, which you can solve by Quadratic Formula (if factoring isn't obvious).

*you get to finish this job.*