You use the FOIL method, and how you do this is -
(x - 7) (x + 8)
Multiply the first x by both numbers in the second factor. Which means, you multiply x by x and 8, the two in (x + 8).
With this, you get -
x^2 + 8x
Then do the same thing with -7.
-7x - 56
Then combine the two.
x^2 + 8x - 7x - 56
Combine like terms.
x^2 + x - 56
So now, 7 x 8 is 56
And -7 + 8 would be 1. And that is the value of “x” which is b in the form a^2x + bx + c.
Now with this, you take those two numbers and make the factors =
(x + 8) (x - 7)
Then you set these equal to 0.
x + 8 = 0
Subtract the 8 from both sides.
x = -8
————
x - 7 = 0
Add the 7 on both sides.
x = 7
Answer: A
Answer:
x > 3
Step-by-step explanation:
This is based on the concept 'when a negative number is multiplied to both sides of the inequality, the sign gets reversed. For example, x > - 2 when it is multiplied by - 1, it becomes - x < 2.'
*only when the number is -ve.
Similarly, in this question, multiply both sides by - 1.
2x > 6
x > 6/2
x > 3
For more : take - 5 > - 2, as you know
Note that 5 is actually greater than 2. To make this true we change signs
X=2 or -7(answer choice A)
