SOLUTION: Please help me by showing me how to do these step by step? I would highly appreciate it! 1. z to the fourth power + 8z to the third - 9z^ = 0 2. (y - 7)(2y^ + 7 - 15) = 0

Hi, 

1) z^4 + 8z^3 - 9z^2 = 0 

always begin by looking for a common factor in the terms

z^2(z^2 + 8 - 9) = 0

factor trinomial as two products if possible

z^2(z+9)(z-1)

roots are x= 0, x= -9 x = 1



2)(y - 7)(2y^ + 7 - 15) = 0

factor trinomial as two products if possible

(y - 7)(2y^ + 7 - 15) = 0

(y - 7)(2y^ -3)(y + 5) = 0

roots are y = 7, y = 3/2 and y = -5