Element X is a radioactive isotope such that every 14 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 80 grams, how much of the element would remain after 18 years, to the nearest whole number?

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8

isn't it a pentagon? sense [3 (triangle) + 4 (rectangle)] - 2 (triangle and rectangle connected) = 5 (pentagon)

the correct answer would be c

step-by-step explanation:

total income = price of one ticket   *   number of tickets sold

  y                 =     4                                   x

so the equation is y=4x     with x≥0   because number of tickets sold can not be negative

thus the equation is a semi -line with an end point at

(0,0)

passing through :

x=1     y=4(1) = 4   so through (1,4)