Ariana starts with 100 mg of a radioactive substance. The amount of the substance decreases by 20% each week for a number of weeks w

europa2433

europa2433

step-by-step explanation:

x=-7

step-by-step explanation:

x+3=-10

-10+3=-7

x=-7

this is a direct variation proportion. y = kx

y is the total amount due, k is the constant of variation, and x is the number of texts sent.

plug in the 3.20 and the 16 to solve for the "k". this is the constant of proportionality. it is the value that will not change.

3.20 = k(16). solving you get $.20 per text.

the equation would then be y = .20x