Question

The function g is defined by g(x)=ax−7, where a is a constant. Find a, if the graph of g passes through the point ( 1/3 ,−2).

Answer 1

a = 15

Explanation:

The graph of function g(x) is described by g(x)=ax−7, or y = ax−7.

y = g(x)=ax−7 passes through (1/3, -2). We can subst. -2 for y and 1/3 for x to determine the value of the coefficient a:

-2 = g(1/3) = a(1/3) - 7

Solve for a. First, add 7 to both sides: 5 = a(1/3).

Next, multiply both sides by 3: 15 = a, or a = 15.