Step-by-step explanation:
Because the length of ST is calculated using pythagorean theorem:

Where the square of the hypotenuse is equal to the sum of squares of the other two sides of a right triangle. In this case, the hypotenuse is ST and the other two sides are distances between S and T over the X and Y axis. Those are easily calculated:

Where x is the distance between S and T over X axis and Y distance over Y axis, sx and tx are X coordinates of S and T, sy and ty are Y coordinates of S and T.
Using that formula, you get that y = 17 and x = 8.
Back to the pythagorean theorem, if we put those number in the formula of the pythagorean theorem, we get something like this:

And finally, the correct answer is in fact 353.
Answer:
that answers wrong
Step-by-step explanation:
Answer:
y = 1/2x + 7
Step-by-step explanation:
Parallel lines have the same slope.
Therefore the new equation will have a slope(m) = 1/2
Substitute m = 1/2 and point (-2, 6) into y = mx + b to solve for "b"
y = mx + b
6 = 1/2(-2) + b
6 = -1 + b
7 = b
The new equation: y = mx + b
y = 1/2x + 7