A substance has a half-life of 6 years. If 20 pounds are present initially, how much will remain after 2 years?

16.66pound

Step-by-step explanation:

roughly 16.66 pound

if in 6 years it become half which is =10

then 10÷6= 1.67

then 1.67 pound is decayed every year.

in 2 years it decay 1.67×2= 3.34

so , the remaining is 20-3.34=16.66pound

13.33%

say 50 oranges, then 100 apples

80 are red, 20 are yellow

total fruit = 150

20chances out of 150 for yellow

20/150 = 13.33%

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.