Question

4×10^-2+9×10^-3+9×10^-4

Answer 1

$4*10^{-2}+9*10^{-3}+9*10^{-4}=10^{-2}(4+9*10^{-1}+9*10^{-2})= \\ =10^{-2}(4+0.9+0.09)=10^{-2}*4.99=0.0499$

Answer 2

To add these numbers together, you'll want to ensure that they all have the same exponent, which, in this case, is 10^-2. You can rewrite the numbers with the same exponent and then add them:

4×10^-2 + 9×10^-3 + 9×10^-4

= (4×10^-2) + (0.9×10^-2) + (0.09×10^-2)

Now that they have the same exponent (10^-2), you can add the coefficients:

= (4 + 0.9 + 0.09) × 10^-2

= 4.99 × 10^-2

So, 4×10^-2 + 9×10^-3 + 9×10^-4 is equal to 4.99×10^-2.