Oh dear lord me and tell me how you got your answer !

Solution of Question A:

Hence, 21.1 is the answer in decimal form.

Solution of Question B:

=> (-3 + 6)² ÷ 4.5

=> (3)² ÷ 4.5

=> 9 ÷ 4.5

=> 2.0

Hence, 2.0 is the answer in decimal form.

Solution of Question C:

=> 12.5 - 1.4 × 2²

=> 12.5 - 1.4 × 4

=> 12.5 - 5.6

=> 6.9

Hence, 6.9 is the answer in decimal form.

Solution of Question D:

=> 2(3/4 - 1) + 0.35

=> 2(-1/4) + 0.35

=> -1/2 + 0.35

=> -0.5 + 0.35

=> -0.15

Hence, Option A is the correct answer.

Solution of Question E:

=> Volume = L × B × H

=> 12.05 × 3.86 × 5.11

=> 12.05 × 19.7246

=> 237.68143

=> 237.7 (To the nearest tenth)

Hence, Option C is the correct answer.

Hoped this helped.

  about 5.6 days

step-by-step explanation:

we can fill the given information into the decay equation and solve for the value of t at which half the sample remains.

the half-life is about 5.6 days.