Urgent help plz. The expression -140 + 20m represents a submarine that began at a depth of 140 feet below sea level and ascended at a rate of 20 feet per minute. What was the depth of the submarine after 4 minutes? could you help with the math part too?

Which values for a and b will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

What is the point-slope equation of a line with slope -5 that contains the point (6,3)

(03.03 mc) choose the graph below that correctly represents the equation 2x + 4y = 24. (5 points) select one: a. line through the points 0 comma 6 and 12 comma 0 b. line through the points 0 comma negative 6 and 12 comma 0 c. line through the points 0 comma negative 12 and 6 comma 0 d. line through the points 0 comma 12 and 6 comma 0