If A=(-1, -3) and B=(11,-8), what is the length of AB? A. 14 units
B. 13 units
C. 12 units
D. 11 units

9514 1404 393

  B.  13 units

Step-by-step explanation:

The distance formula can be useful.

  d = √((x2 -x1)² +(y2 -y1)²)

  d = √((11-(-1))² +(-8-(-3))²) = √(12² +(-5)²) = √(144 +25) = √169

  d = 13

The length of AB is 13 units.

If you're familiar with a few of the small Pythagorean triples, you would know that for integer coordinates, an integer answer is most likely to be 13. The x- and y-differences in coordinates being 12 and 5 confirm that the (5, 12, 13) triple is being used here.

There are no Pythagorean triples with hypotenuse values of 11, 12, or 14. (3, 4, 5) can be doubled to give (6, 8, 10), but 10 is not a choice.

$4034.40

the perimeter of the field is the sum of the lengths of the four sides:

47 yd + 158 yd + 47 yd + 158 yd = 410 yd

the cost of 3 ft (1 yd) of fence is 3×$3.28 = $9.84.

so the cost of jake's wood perimeter fance is

(410 yd) × ($9.84 /yd) = $4034.40

94

step-by-step explanation:

average the numbers and use a variable to figure out the minimum to get a 90.

(79+94+91+92+x)/5=90

x = 94