Please help me

y=-4x-23
y=-2x-8

According to the number line, what is the distance between points a and b? v ++ + + + + -16 -14 -12 -10 -8 + 6 + 4 + -2 + 0 + 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 o6 units o 7 units 12 units o 14 units

Evaluate the expression for the given value of the variable 7a - 4a for a =8

What is the distance between point a and b