Answer:
I think the answer would be the very first one.
they all need to have '' ( ) '' in them.
if a number is outside of that, it needs to at least have a letter beside the number
here's an example
Factored form:
2x(x + y)
not factored:
2(x - y)
but for the first one, it's correct from the rest of them.
y=x^2 + x - 2
x + y = 1
Replace y in the second equation:
x + x^2 + x -2 = 1
Simplify:
x^2 + 2x -2 = 1
Subtract 1 from both sides:
x^2 + 2x -3 = 0
Factor:
(x-1) (x+3) = 0
Solve for both x's:
x = 1 and x = -3
Now replace x in the second equation and solve for y using both x values:
1 + y = 1, y = 0
-3 + y = 1, y = 4
Now you have (1,0) and (-3,4) as solutions for (x,y)
XY = x times y:
1 x 0 = 0
-3 x 4 = -12
The answer would be -12
x =
or x = - 
consider the factors of the product 6 × - 4 = - 24 which sum to the coefficient of the x- term ( + 5)
the factors are + 8 and - 3 ( split the middle term using these factors
6x² - 3x + 8x - 4 = 0 ( factor by grouping )
3x(2x - 1) + 4(2x - 1 ) ( take out common factor of (2x - 1) )
= (2x - 1)(3x + 4) = 0
equate each factor to zero and solve for x
2x - 1 = 0 ⇒ x = 
3x + 4 = 0 ⇒ x = - 