It is d, you first have to see how many times 0.2 goes into 18
Well, you have to do it with the substitution method now it's not easy, it takes some time to get used to it. I'm not really sure how to explain it but if you go on Khan Academy it will show you how to do it.
Is it supposed to be equal to something, maybe "0"? You wouldn't be able to solve this without that.
1)Rewrite the table:
70, 49, 34.3, 24.01, 11.807 {The original size of the wound =70}
2) write the quotient of each number by the number before & notice the value:
49/70= 0.7
34.3/49 = 0.7
24.01/34.3 =0.7
16.0807/24.01 = 0.67 ≈0.7
You notice this is a geometric progression with r 0.7
The last term in a GP =ar^⁽ⁿ⁻¹⁾
3) Domain and Range of this function:
Last term = a₁.rⁿ⁻¹. let last term be y==> f(n) = y =70(0.7)ⁿ⁻¹
or f(n) = y = 70(0.7)ⁿ / 0.7==> f(n) = [(0.7)ⁿ ]/ 100.
This is a decreasing exponential function where the coefficient
raised to n is < 1.
The domain is for all n>= 0.
When n→∞, f(n)→0; For n=0==>f(n) =70. So the range of f(n) is:<=70
$864 all you had to do was multiply 216 by 4 and 380 by 4 to get 1520 and 656 subtract that to get 864