Which expression is equivalent to (0.23t-0.3)-(0.7t-0.23)

What are the coordinates of the point is 1/4 of the way from a (-6, -3) to b (6, 1)? a. (-3, -2) b. (0, -2) c. (-1, 0) d. (3, 2)

The graph represents the gallons of water in a water tank with respect to the number of hours since it was completely filled

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.