Determine the y-value of each ordered pair based on the given x-value. 5. y = 6x - 15; (8, ),(-1, ),(5, ) 6. y = -4x+9; (-5, ), (2, ),(4, ) 7. y = 2x – 1; (-4, ),(0,),(7) 8. y = -x +9; (-9),(1, ),(5, )