Compute: {{MATH_50}} {{CMD_51}} We want to substitute for {{MATH_52}}. But the variable ``{{MATH_53}}'' has already been used{{CMD_54}} OH NO! Never fear! We can substitute with whatever variable that we want. In particular, let us use ``{{MATH_55}}'' for this problem. So we let {{MATH_56}} and then {{ENV_57}} Thus {{ENV_58}} {{CMD_59}} Recall: {{MATH_60}} So, we can call a variable {{MATH_61}} by any other name and ``it would smell as sweet".