Answer:
Step-by-step explanation:
Recursive formula
tn = t_n-1 / 4
t2 = t1 / 4
t2 = 10240
t1 = 10240 / 4 = 2560
Explicit formula
tn = 10240 / 4^(n-1)
t4 = 10240 / 4^(4 - 1)
t4 = 10240 / 4^3
t4 = 10240 / 64
t4 = 160
t8 = 10240 / 4^7
t8 = 0,625
She gonna need to buy 32 boxes because 315 divided by 10 is 31 r 5 and also you can't buy 31 boxes because 5 kids aren't gonna have pencils so she needs to buy 32 boxes of pencils
You must graph the two given lines and find their point of intersection. It is (10,5). Shade the areas BELOW each of the 2 lines. One line intersects the y-axis at (0,15) and the other line intersects the x-axis at (12.5,0)
Thus, you have an area defined by the vertices given above.
What to do next? Steal the coordinates of each point and subst. them into the given objective function P = 15x + 20y. For exampel, for (12.5,0), the value of P is 15(12.5) + 20(0) = 187.5.
Find P for each of the remaining 3 vertices.
The largest value of P is the answer to this question.
Okay so the area of a rectangle x by y with a border of width b will be:
A=(x+2b)(y+2b)
A=xy+2bx+2by+4b^2 we are told that A=320, x=11, and y=15 so now we have:
320=165+22x+30x+4x^2, now I am using x as the border width...
4x^2+55x+165=320 is the equation that they listed..
...
4x^2+55x-155=0 using the quadratic formula for efficiency...
x=(-55±√5505)/8 since x>0
x≈2.399 which for some unknown (incorrect) reason they rounded to
x=2.5
So in short, your answer is a)
Your answer is going to be B. $14.75, hope this helps!!