Answer:
x = 1.8 x 10² Ms⁻¹.
Explanation:
First, let's see the expression of x:
[tex]x=(7.4\cdot10^3M^{-2}s^{-1})\cdot(0.29M)^3.[/tex]Let's eliminate the parenthesis:
[tex]x=7.4\cdot10^3M^{-2}s^{-1}\cdot0.29^3M^3.[/tex]We can 'cancel' the M (molar) term. Remember that we have the following exponent law:
[tex]a^ma^n=a^{m+n}.[/tex]So we can apply this to M: we have to sum -2 and 3 to obtain 1 (-2+3 = 1):
[tex]x=7.4\cdot10^3Ms^{-1}\cdot0.29^3.[/tex]And finally, we just have to multiply 7.4 x 10³ by 0.29³ using the correct units that we already know (Ms⁻¹), as follows:
[tex]x=180.48Ms^{-1}\approx1.8\cdot10^2Ms^{-1}.[/tex]As we have to give the answer with 2 significant figures, the answer would be x = 1.8 x 10² Ms⁻¹.