*not multiple choice*

u^-3 = 1/125

y - 1 = 4y - 2/3 * not sure how to do
this

what is the y intercept of the line?
y= -3x - 5 * my answer is 5

when 40 is added to the number miles she ran last week..the result is the same as adding 10 to 4 times the number she ran last week. * not sure how to do this, because I have to find the miles she ran last week.

what is the slope of the line 4y - 6x + 12 = 0 in simplest form? * not sure how to do this

u^-3 = 1/125

u^-3 = 5^-3
u = 5

y-1 = 4y - 2/3
3y-3 = 12y-2
9y = -1
y = -1/9

The y-intercept is where x=0. Clearly when x=0, y = -5, not 5.

If she ran x miles, then we know that
x+40 = 10+4x
x = 10

If you want the slope, try writing the equation is slope-intercept form:
4x-6y+12 = 0
6y = 4x+12
y = 4/6 x + 2
So, the slope is 4/6 or 2/3