The area of a rectangular region is 6.2 × 10^3 square feet. The length

of the rectangular region is 1.55 × 10^2 feet. How much does it cost to

surround the region with a border that costs $0.80 per foot?

312

Step-by-step explanation:

First we need to determine the width

A = l*w

6.2 * 10 ^3 = 1.55 * 10 ^2 * w

Divide each side by 1.55 * 10 ^2

6.2 ^ 10 ^3  /1.55 * 10 ^2 = 1.55 * 10 ^2 * w / 1.55 * 10 ^2

Changing from scientific notation to standard

6200/155 = w

40 = w

Then we need to determine the perimeter

P = 2(l+w)

P = 2( 155+40)

P =2( 195)

P = 390

Now multiply by the price

390 *.80

312

( ͡° ͜ʖ ͡°)

step-by-step explanation:

just copy and paste it.

visit this site for a tutorial ʖ-tutorial-flash-cards/

there are lots of ways.   pick's theorem tells us if the vertices are lattice points the area a is

a = b/2 + i - 1

where b is the number of boundary lattice points and i is the number of interior lattice points.

in the figure i count b=16, i=50 so

a = 8 + 50 - 1 = 57

let's try the shoelace formula.   the area is half the sum of the cross products of the sides.  

a(-2,6)   -2(2)-6(-5) = 26

b(-5,2)   -5(-3) - 2(-2) = 19

c(-2,-3) -2(-3) - (-3)(4) = 18

d(4,-3)   4(3) - (-3)(5) = 27

e(5,3)   5(3) - 3(1) = 12

f(1,3)     1(6) - 3(-2) = 12

a(-2,6)

each of the cross products is twice the area of the triangle with the associated side and one vertex the origin. so the area of abo=26/2=13.

area = (1/2) (26 + 19 +   18 + 27 + 12 + 12) = 57

that checks!