Use the approximate doubling time formula (rule of 70) for the case described below. Discuss whether the formula is valid for the case described. An economic indicator is increasing at the rate of 7% per year. What is its doubling time? By what factor will the indicator increase in 2 years?
What is its doubling time?
years
(Type an integer or decimal rounded to the nearest tenth as needed.)
By what factor will the indicator increase in 2 years?
(Type an integer or decimal rounded to the nearest hundredth as needed.)
Is this formula valid in the case described?
Yes
No
Click to select your answer(s).

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1

16 is the absolute value

step-by-step explanation:

i need more details sorry

step-by-step explanation: