Question

Do we use foil in this question?? Can you help me solve it?Foil means First,outer,inner,last(z+4) (z-4)

Answer 1

Yes we may also use FOIL

$\mleft(z+4\mright)(z-4​)=z^2+4z-4z-16=z^2-16$

but this is the same as

$(x+y)(x-y)=x^2-y^2$

You may simply square the first and second term , then use the negative sign. but this was actually solved using FOIL