Question
Evaluate $: 9^{\frac{5}{2}}-3 \times 8^0-\left(\frac{1}{81}\right)^{-\frac{1}{2}}$
✓
Answer
$ 9^{\frac{5}{2}}-3 \times 8^0-\left(\frac{1}{81}\right)^{-\frac{1}{2}}$
$ =\left(3^2\right)^{\frac{5}{2}}-3 \times 1-\left(\frac{1}{3^4}\right)^{-\frac{1}{2}}$
$ =3^{2 \times \frac{5}{2}}-3-3^{-4 \times\left(-\frac{1}{2}\right)}$
$ =3^5-3-3^2$
$ =243-3-9$
$ =231$
$ =\left(3^2\right)^{\frac{5}{2}}-3 \times 1-\left(\frac{1}{3^4}\right)^{-\frac{1}{2}}$
$ =3^{2 \times \frac{5}{2}}-3-3^{-4 \times\left(-\frac{1}{2}\right)}$
$ =3^5-3-3^2$
$ =243-3-9$
$ =231$
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