Question 363363
Use the difference of squares formula {{{(A-B)(A+B)=A^2-B^2}}} to get:



{{{(1-3/4)(1+3/4)=(1)^2-(3/4)^2=1-9/16=16/16-9/16=(16-9)/16=7/16}}}



So {{{(1-3/4)(1+3/4)=7/16}}}