Answer:
We see the solutions are x <= -4 Union with x >= 7
(-♾ ,-4]or [7,♾)
for x^2 -3x - 28 >= 0
Step-by-step explanation:
x^2 -3x - 28 >= 0
I will use the Diamond method for factoring.
Factor -28 = -7 * 4 and -7 + 4 = -3
x^2 - 7x + 4x - 28 >= 0
x(x - 7) + 4(x - 7) >= 0
(x + 4)(x - 7) >= 0
Here we create 2 number lines.
----------( -4)---------0 ----------------7-------------
-----------0 ++++++++++++++++++++++++++++++++ (x + 4)
--------------------------------------------0+++++++++++++++(x - 7)
+++++++0------------------------------0+++++++++++++++ (x+4)(x-7)
We see the solutions are x <= -4 Union with x >= 7
(-♾ ,-4]or [7,♾)
