Answer
a. B. 1
b. C. -1
c. B. 1
d. C. -1
Work Step by Step
According to page 267, $a^{0}=1$ (where $a$ is a nonzero real number). In other words, we know that any nonzero real number raised to a power of 0 will equal 1.
Therefore,
a. $9^{0}=1$
b. $-9^{0}=-(9^{0})=-(1)=-1$
c. $(-9)^{0}=1$
d. $-(-9)^{0}=-(1)=-1$