Question 257634
The values of a, b, c, and d are 0, 1, 2, and 3, although not necessarily in that order. What is the maximum value of the expression c⋅a^b – d ?
<pre><font size = 4 color = "indigo"><b>
We can't use 0 at all in the first term since the first 
term would be 0 unless the exponent b was 0 and then the 
most the first term could be would be 3, then we'd have 
to take d away from that making the value even smaller.

Therefore d must be 0.

We can't use 1 as the exponent b or the base a, since 
the most we could get would be 6. So 1 must be the 
coefficient a and since {{{3^2=9}}} is greater than {{{2^3=8}}}.
So we must have

{{{1*3^2 - 0=9}}}, where a=3, b=2, c=1 and d=0.

The maximum is 9.

Edwin</pre>