Multiply 2.7 x 10^-4 by 6.3 x 10⁶ and leave your answers in standard form

If 9^{(2 - x)} = 3, find x

In what number base is the addition 465 + 24 + 225 = 1050?

Simplify \(\frac{1\frac{7}{8} \times 2\frac{2}{5}}{6\frac{3}{4} \div \frac{3}{4}}\)

If Un = n(n² + 1), evaluate U5 - U4