given the relation {(-8, 4), (-4, 5), (x, 6), (4, 7)}, which value of x will make this relation a function
(A) 0 (B) -4 (C) -8 (D) 4
slope:
(y2-y1)/(x2-x1)
bring any points which you want:
(4, 7) and (-4, 5)
(7-5)/4-(-4)=2/8
(x, 6) and (-8, 4)
(6-4)/(x-(-8))=2/8
2/x+8=2/8
x=0
Answer: (A) 0
f(x)=1/4x+6
