6. What is the tens' digit of the largest 4-digit even number which uses each of the digits 5, 7, 8, and 9 exactly once? A 9
B) 8
C) 7
D) 5

B)

Step-by-step explanation:

8 is even number which uses each of the digits exactly once.

y=3x+4

step-by-step explanation:

given the points a(0,4) and b(-4, -8)

eqn of line ab: (y-4)/(x-0)=(-8-4)/(-4-0)

(y-4)/x=-12/-4=3

y=3x+4