How many solutions does the system formed by x − y = 4 and ay − ax + 4a = 0 have for a nonzero number a? Explain pls

Can someone me do math because i am having a breakdown rn because i don’t get it

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days

15 points! write the slope-intercept form of the equation of the line through the given point with the given slope. use y-y = m(x-x) to solve. through (2,5) slope= undefined