The diagonal of a rectangle = sqrt(w^2 + l^2)
w = width
l = length
In this problem,
The diagonal = 20 in
w = x
l = 2x + 8
Let's plug our numbers into the formula above.
20in = sqrt((x)^2 + (2x + 8)^2)
Let's simplify the inside of the sqrt
20 in = sqrt(5x^2 + 32x + 64)
Now, let's square both sides.
400 = 5x^2 + 32x + 64
Subtract 400 from both sides.
0 = 5x^2 + 32x - 336
Factor
0 = (5x - 28)(x + 12)
Set both terms equal to zero and solve.
x + 12 = 0
Subtract 12 from both sides.
x = -12
5x - 28 = 0
Add 28 to both sides.
5x = 28
Divide both sides by 5
x = 28/5
The width cant be a negative number so now we know that the only real solution is 28/5
Let's plug 28/5 into our length equation.
Length = 2(28/5) + 8 = 56/5 + 8 = 96/5
In conclusion,
Length = 96/5 inches
Width = 28/5
Answer:
9. x=-6, y=0
10. x=-9, y=-10
11. x=3, y=-1
Step-by-step explanation:

Multiply the first equation by 2.

Add the equations.


We figured out x now we have to figure out y. To figure out y plug in x into any equation.




Your answer is x = -6 and y = 0 for number nine.

Change the signs of the second equation becuase 3y and 3y are both positive. We need one of them to be negative.

Add them.


Now we have to figure out y.




x=-9 and y=-10 is your answer to number ten.








x=3 and y=-1 is the answer to number eleven. I hope this helps! Let me know if I got anything wrong.
-4r+5=25 -4r=20 r=-5
typing this to get to 20 characterssss
Answer:
The value of A is 20
Step-by-step explanation:
To find the answer, note that all triangles have a interior degree measurement of 180. Set the sum of the angles equal to 180.
71x - 1 + 20x + 90 = 180
91x + 89 = 180
91x = 91
x = 1
Now we can use this in the A angle to find the value.
A = 20x
A = 20(1)
A = 20