I believe it is -1 since -3 times -1 equals 3 and the rate of change is based on the slope of a line
4/5(v - 7) = 2...distribute the 4/5 thru the parenthesis
4/5v - 28/5 = 2 ...multiply everything by 5
4v - 28 = 10...add 28 to both sides
4v = 10 + 28
4v = 38
v = 38/4 reduces to 19/2 or 9 1/2 <==
The dimensions of the carton are:
10 x 10 x 10 [inch OR unit cubes - it's the same since cubes' dimensions are 1 x 1 x 1 inch)
I attach the explanation below.
For the first one it’s b and I’m sorry but I’m not sure about the second