Answer:
k = 3 or k = -4
(Anyone can correct me if I'm wrong)
Step-by-step explanation:
In this diagram we see that 80 and 3x+4y are both vertical angles and vertical angles are congruent or always equal so we can set those two equations equal to each other then we can see that a line splits two angles making them supplementary (they equal 180 degrees) So we can have another equation, the two equations are:
3x+4y=80 and 3x+4y+7x-8y=180 (add like terms to simplify and get 10x-4y=180
Then use elimination to get rid of the y variables
10x-4y=180 (plus)
+3x+4y=80 (the negative 4 and positive 4 cancels each other out so you are left with:)
13x=160 (divide by x)
x=12.30769 which can be rounded to x=12.31
Then we have to plug in x into the first equation:
3(12.31) + 4y = 80
36.93 + 4y = 80 (subtract 36.93 from 80)
4y = 43.07 (divide)
y=10.7675 or rounded to 10.77
so x=12.31 and y=10.77
It’s about -1.5555 I think
Answer:
(A) 40 km
(B) 90 km
(C) 180 km²
Step-by-step explanation:
To find the missing side of this triangle, let's use the Pythagorean theorem.
, assuming that a and b are legs, and c is the hypotenuse.
Assuming the 9km side is a, we need to find the value of b, so we can substitute into the equation.
So, the length of the missing side is 40. Now that we know this piece of information, we can find the perimeter and area of the triangle.
The perimeter is all the sides added together, so 
km is the perimeter.
The area are the two legs multiplied divided by 2.
So,
So the area of this triangle is 180 cm²
I hope this helped!
