0.4(20-10m)+ 2.5-2m-12.5 the answer is -6 -2 but i need the explaination

Find percent notation for 0.008 0.008=

Marking brainliest for original answer.. are these two triangles similar? how can you tell?

Situation: find the age of the skull to the nearest year, enter the correct answer. a hiker in africa discovers a skull that contains 32% of its original amount of c- 14. done n = noekt 00000 no = inital amount of c-14 (at time t = 0) n = amount of c-14 at time t k = 0.0001 t = time, in years