Solving systems of equations elimination

Which value is not a solution of 8x^3 – 1 = 0

Which shows the correct lengths of side c in both scales? scale 1: 45 m; scale 2: 60 m scale 1: 60 m; scale 2: 45 m scale 1: 36 m; scale 2: 27 m scale 1: 27 m; scale 2: 36 m mark this and return save and exit

Which equation represents a direct linear variationa. y=x2b. y=2/5xc. y=1/xd. y=x+3