Question 197952
<font face="Garamond" size="+2">


Note that


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 7^{a+2} = 7^2\cdot7^a] and


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 49(7^{a-2}) = 7^2\cdot7^{a-2} = 7^{a-2+2}=7^a]


So:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 7^{a + 2} - 8(7^{a+1}) + 5(7^a) + 49(7^{a-2}) = 49\cdot7^a-56\cdot7^a+5\cdot7^a+7^a=-7^a]



John
*[tex \LARGE e^{i\pi} + 1 = 0]
</font>