Y = 4x - 7 is a line with a slope of 4 and y-intercept of -7.
plug in any X value, for example 1 and you get the following
y = 4(1) - 7
y = -3
(1,-3) is a point that satisfies the equation y = 4x - 7
A number is a perfect square (or a square number) if its square root is an integer; that is to say, it is the product of an integer with itself. Here, the square root of 20 is about 4.472. Thus, the square root of 20 is not an integer, and therefore 20 is not a square number.
11! = 39,916,800
The erased digits are 1, 0, 0.