Someone please help I don’t understand simultaneous equations

Initially 100 milligrams of a radioactive substance was present. after 6 hours the mass had decreased by 4%. if the rate of decay is proportional to the amount of the substance present at time t, find the amount remaining after 24 hours. (round your answer to one decimal place.)

If the value of x increases by 5, how does the value of m(x + 3) change? a) it increases by 5m. b) it increases by 8m. c) it decreases by 5m. d) it decreases by 8m.

Apolygon is shown on the graph: a polygon is shown on the coordinate plane. vertices are located at 3 comma 5, 1 comma 3, 1 comma 1, 2 comma 0, 4 comma 0, 5 comma 1, and 5 comma 3. what effect will a translation 3 units down and 2 units left have on the polygon? be sure to address how it could impact the angles, side lengths, and congruency between the original pre-image and the image. xd i need