The decay of 942 mg of an isotope is described by the function a(t)= 942e-0.012t, where t is time in years. find the amount left after 71 years. round your answer to the nearest mg.

Applying the exponential function, it is found that the amount after 71 years is of 402 mg.

The exponential equation for the amount after t years is given by:

For the amount after 71 years, we find A(71), thus:

The amount after 71 years is of 402 mg.

A similar problem is given at link

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°

you never say the total so we cant find the percentage used for petrol

step-by-step explanation: