Answer:

Step-by-step explanation:
S = (x1,y1) = (0,-5)
T = (x2,y2) = (-8,-7)
<u>Using distance formula to find the length of ST</u>.
![|ST|= \sqrt{(x_2-x_1)^2+(y_2-y_1)^2} \\\\|ST| = \sqrt{(-8-0)^2+(-7-(-5))^2} \\\\|ST| = \sqrt{(-8)^2+(-7+5)^2} \\\\|ST| = \sqrt{64+(2)^2}\\\\|ST| = \sqrt{64+4} \\\\|ST| = \sqrt{68} \\\\|ST| = 8.2 \ units\\\\\rule[225]{225}{2}](https://tex.z-dn.net/?f=%7CST%7C%3D%20%5Csqrt%7B%28x_2-x_1%29%5E2%2B%28y_2-y_1%29%5E2%7D%20%5C%5C%5C%5C%7CST%7C%20%3D%20%5Csqrt%7B%28-8-0%29%5E2%2B%28-7-%28-5%29%29%5E2%7D%20%5C%5C%5C%5C%7CST%7C%20%3D%20%5Csqrt%7B%28-8%29%5E2%2B%28-7%2B5%29%5E2%7D%20%5C%5C%5C%5C%7CST%7C%20%3D%20%5Csqrt%7B64%2B%282%29%5E2%7D%5C%5C%5C%5C%7CST%7C%20%3D%20%5Csqrt%7B64%2B4%7D%20%5C%5C%5C%5C%7CST%7C%20%3D%20%5Csqrt%7B68%7D%20%5C%5C%5C%5C%7CST%7C%20%3D%208.2%20%5C%20units%5C%5C%5C%5C%5Crule%5B225%5D%7B225%7D%7B2%7D)
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Answer:


Step-by-step explanation:
Note that the entire segment RT is the combined lengths of RS and ST. So:

We know that RT is 108, RS is (9y+5), and ST is (3y+7). Substitute:

On the right, combine like terms:

Add:

Subtract 12 from both sides. The right cancels:

Divide both sides by 12:

So, the value of y is 8.
To find RS and ST, substitute 8 for y. So:

Substitute 8 for y:

Multiply:

Add:

Do the same for ST:

Substitute 8 for y:

Multiply:

Add:

The correct answer is 22 miles because 5+8+9=22
Hope this helped :)