Indices: Two variables x & y satisfy the equation y = 3*4^x. Find 'a' if (a,6) lies on graph. Find 'b' if (-1/2,b) also lies on the graph.

[reggiwilliams]

Came across this question in a past exam paper.
You will see how I solved it.
Is it as simple as that or am I missing something?

 

[eipi45]

looks right to me

 

[lookagain]

Is it as simple as that or am I missing something?

Don't write the b-value as a mixed number. Instead, use an improper fraction.
After your second line from the bottom, write
$\displaystyle \ y \ = \ \dfrac{3}{2} \$ and then write $\displaystyle \ b \ = \ \dfrac{3}{2} \$ on the last line.