X means everything in algebra. It is a variable, which means that its meaning changes based on context. For example, x could be time, but it could also be cars. x is what all Mathematicians chase after and it is also the greatest tool at their disposal. x is generally called an independent variable because its value determines the output of a function. y, on the other hand, is the result of fooling around with x. It's a dependent variable, which means that y changes when x changes.
Take, for instance, the following function:
y = x + 3
Let's set x = 3.
y = (3) + 3
y = 6
As you can see, what we input as x determines what y outputs.
In (4, 1) 4 represents x, and 1 represents y
y = 3x + 1
1 = 3(4)+1
1 = 12 + 1
1 ≠ 13 ← sides are not equal so (4, 1) is not a solution to y=3x+1
The cross-section of a cube, if the slice is made parallel to one of the faces, would be a square congruent to the face of the cube.
Suppose x-6 is listed as a possible answer. That is zero if x = 6. So put x=6 into the original x^2 + 4x - 60 to get 6^2 + 4*6 - 60 = 36 + 24 -60 = 0. hence x-6 is a factor.
Answer (x-6)
on this hand :x-5 is not a factor, because plugging x=5 into does not work.