Number one, is 430 divided by 18. 430/18 = 23.8888889 = rounding the number should make 23.4
2.) 7a^2 + 50a + 7 = 7a^2 + a + 49a + 7 = a(7a + 1) + 7(7a + 1) = (a + 7)(7a + 1)
3.) 3x^2 + 11x - 20 = 3x^2 - 4x + 15x - 20 = x(3x - 4) + 5(3x - 4) = (x + 5)(3x - 4)
4.) x^2 + 7x - 18 = x^2 - 2x + 9x - 18 = x(x - 2) + 9(x - 2) = (x + 9)(x - 2)
The second one doesn't represent a function, because for some values of "x", you get two different values for "y" (which should not happen, if that were a function).
In every function, you must have a
single "y" value for each "x" in the domain.
__________
In order to see it better, you can trace a vertical line onto that graph.
If that line and the graph intersects in more than one point, then that graph doesn't represent a funcion.
Look into the attached picture and see. That vertical red line and the graph intersects in two distinct points. Therefore, it can't represent a function.
Any doubt? Please, comment below.
I hope it helps. :-)
The correct answer is B. You can figure it out by comparing the two tables