To find x, first we'll split the triangle in two right triangles.
The first triangle will be the one with sides (8,x+4,y) and the second triangle will be the one with sides (12,2x+1,y).
As you can see, these two triangles share the side 'y'.
To solve we'll do the following; first solve for 'y' by applying the Pythagorean theorem in the second triangle, and finally solve for 'x' applying Pythagorean theorem in the first triangle.
From the second triangle (12,2x+1,y) we solve for 'y' by writing:

Now that we know 'y^2' we apply Pythagorean Theorem in the first triangle (8,x+4,y)


Now you solve the quadratic equation, you'll get a positive and negative value; as this are lengths, you take the positive and get:
Answer:
C
Step-by-step explanation:
the size of the steps gives you the number before x
and the -1 , +4 is just what left when x equals zero, so in the two tables we find it in row two
Answer:
The distance traveled at a constant speed is directly proportional to the time of travel. If Olivia traveled 112 miles in 3.5 hours, how many miles will Olivia travel in 8.9 hours at the same constant speed?
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Proportion:
x/8.9 = 112/3.5
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x = 8.9(112/3.5)
x = 284.8 miles
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Cheers,