Answer:60 miles per hour
Step-by-step explanation:
Triangular sequence = n(n + 1)/2
If 630 is a triangular number, then:
n(n + 1)/2 = 630
Then n should be a positive whole number if 630 is a triangular number.
n(n + 1)/2 = 630
n(n + 1) = 2*630
n(n + 1) = 1260
n² + n = 1260
n² + n - 1260 = 0
By trial an error note that 1260 = 35 * 36
n² + n - 1260 = 0
Replace n with 36n - 35n
n² + 36n - 35n - 1260 = 0
n(n + 36) - 35(n + 36) = 0
(n + 36)(n - 35) = 0
n + 36 = 0 or n - 35 = 0
n = 0 - 36, or n = 0 + 35
n = -36, or 35
n can not be negative.
n = 35 is valid.
Since n is a positive whole number, that means 630 is a triangular number.
So the answer is True.
The area of the arrow given in the figure is 610 square cm
<h3>Area of composite figure</h3>
The given figure is made up of rectangle and triangle. The area is expressed as:
Area = Area of rectangle + area of triangle
Substitute the given parameters
Area of the arrow = (15*20) + 0.5(31 * 20)
Area of the arrow = 300 + 310
Area of the arrow = 610 square cm
Hence the area of the arrow given in the figure is 610 square cm
Learn more on area of composite figures here: brainly.com/question/21135654
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Answer:
y=4x+10
Step-by-step explanation:
2y-8x-20=0
2y-8x=0+20
2y-8x=20
2y=8x+20
y=4x+10
Hope that will help!!
The answer is the first one I don't know if I am correct through hope that I can help