Final answer:
To find the equation of line u, we need to determine its slope which is the negative reciprocal of the slope of line t. Then, we can use the point-slope form of a linear equation to find the equation of line u.
Step-by-step explanation:
To find the equation of line u, we need to determine its slope. Since line u is perpendicular to line t, its slope will be the negative reciprocal of the slope of line t. The slope of line t is 5/4, so the slope of line u will be -4/5.
Next, we can use the point (10, -8) and the slope -4/5 in the point-slope form of a linear equation, which is:
y - y1 = m(x - x1)
Substituting the values, we get:
y - (-8) = -4/5(x - 10).
Simplifying the equation gives us the equation of line u: y = -4/5(x - 10) - 8.