The product of a variable and a number should be a variable and a number. I think A, b, and d are the answer because they all comprise of a variable (c, t, j) and a number (11, 1/2, 4). C only provides two numbers and no variable
30 is the answer because 30*25=750
According to Vertical Line test, a vertical line only intersect the graph of a function at one point. Among the choices given, x = 4 is a vertical line. So this line cannot intersect the graph of a function at more than one point. The other three would apply. So the answer choices are A, C and D.
