Answer:
4
Step-by-step explanation:
Given in the question a logarithm expression

We will use Exponent of Log Rule

here b = 7
k = 16
So suppose

Now, according to the rule
16 = x²
to find x only take square root on both sides of the equation
x = √16
x = 4
so
= 4
Answer:
a=3
Step-by-step explanation:
The formula for direct proportion is
f = ka
Let f= 42 and a = 7
42 = k*7
Divide each side by 7
42/7 = k7/7
6 =k
f = 6a
Let f = 18
18 = 6a
Divide each side by 6
18/6 = 6a/6
3 =a
So for every gallon he can drive 50 miles. So I think the slope would be 50/-1