Answer:
Part 1) The equation in slope intercept form is 
Step-by-step explanation:
Part 1) Write an equation in slope-intercept form for a line that passes through (3,4) (and has a y intercept of -8)
we know that
The equation of a line in slope intercept form is equal to

where
m is the slope
b is the y-intercept
we have


substitute

solve for m



therefore

Step-by-step explanation:
By Pythagoras' Theorem, 6^2 + 8^2 = x^2.
x^2 = 36 + 64 = 100, x = 10.