Answer:
a = -5
Step-by-step explanation:
(5 - 3)/(5 - a)
2/(5 - a)
perpendicular of 2/(5 - a) = -(5 - a)/2
(a - 0)/(1 - 0) = -(5 - a)/2
a/1 = -(5 - a)/2
2a = -5 + a
a = -5
Answer:
<em>97.5 sq. ft.</em>
Step-by-step explanation:
Im presuming the question asks to find area of the shaded region.
First of all, the total figure is a rectangle. We can write an expression(in words) for the shaded area.
<em>Shaded Area = Area of Rectangle - Area of Small Triangle(White) - Area of Large Triangle(White)</em>
Now, we find respective areas.
Area of rectangle:
length * width = (5+10) * (12) = 15 * 12 = 180
Area of Small Triangle (white):
A = (1/2) * base * height = (1/2) * 5 * (12-3) = (1/2) * 5 * 9 = 22.5
Area of Large Triangle (white):
A = (1/2) * base * height = (1/2) * 10 * (12) = 60
Now, we find area of shaded region:
<em>Shaded Area = Area of Rectangle - Area of Small Triangle(White) - Area of Large Triangle(White)</em>
<em>Shaded Area = 180 - 22.5 - 60 = 97.5 sq. ft.</em>
Answer:
a = 7
Step-by-step explanation:
I think, what you need to do, is first understand how to find the mean of anything: It's quite simple, actually, just add up all the numbers, then divide that number by the number of numbers. So, let's put it in perspective:
10, 3, 4, a, 6, 9, 10
7 is the mean. 7 is the number of numbers.
If, to find the mean is: 10 + 3 + 4 + a + 6 + 9 + 10= 7a ÷ 7, then: 10 +3 + 4+ 6 + 9 +10= 42
42 plus what divided by 7 is the question now.
42 + a ÷ 7= 7
So, 7 times 7, that's 49 minus 42 and you've got your answer: 7
,..........................
