Which set of ordered pairs is not a function? A {(1,4), (2,3), (3,2), (4,3)}
B {(2,3), (3,2), (4,4), (5,2)}
C {(-2,3), (4,1), (2,-1), (1,5)}
D {(-2,3), (1,4), (-2,-1), (1,5)}

)a smart phone has dimensions of 4.9 inches (height), 2.3 inches (width) and 8.0 millimeters (depth). what is the volume of the smart phone in cubic centimeters? (1 in = 2.54 cm)

Find the roots of the equation below. x^2 - 6 + 9 = 0

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?