Answer:
56 minutes
Step-by-step explanation:
An arithmetic sequence has a common difference.
143 - 130 = 13
156 - 143 = 13
169 - 156 = 13
The common difference is 13.
a1 = 130
a2 = 130 + 13
a3 = 130 + 2 * 13
a4 = 130 + 3 * 13
...
an = 130 + (n - 1) * 13
an = 130 + 13(n - 1)
an = 130 + 13n - 13
an = 117 + 13n
an = 13n + 117
We can turn this word problem into the following equation:
x^2 + 85 = (x - 17)^2
x^2 + 85 = x^2 - 34x + 289
-85 -85
_______________________
x^2 = x^2 - 34x + 204
+34x +34x
_______________________
x^2 + 34x = x^2 + 204
-x^2 -x^2
____________________
34x = 204
Divide 34 on both sides
x = 6.
The number is 6.
A trapezoid is a rectangle.
