What is the circumference of a circle with a radius of 4.3 inches in terms of pie

Compare the subtraction problems 6/8 - 5/8 = 1/8 and 6/9 - 7/9 = 1/9 why is the answer to the first problem positive and the answer to the second problem negative

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Rewrite so the subject can be y in the formula d=m-y/y+n