6x² - 5x + -21 = 0
Because this whole equation equals zero, we must simply factorize the first half of the equation, or the left side.
(3x - 7)(2x + 3) = 0
I was never really taught a specific way to factorize, so I usually just guess and check when factorizing. It usually takes a long time, it always gives you the tight answer.
Then, take each equation and make it equal zero.
3x - 7 = 0 AND 2x + 3 = 0
3x - 7 = 0
Add 7 to both sides.
3x = 7
Divide both sides by 3.
x = 7/3
Now, we do our second equation.
2x + 3 = 0
Subtract 3 from both sides.
2x = -3
Divide both sides by 2.
x = -3/2
So, x = 7/3 AND x = -3/2
So, your answer is C) x = 7/3, x = -3/2
~Hope I helped!~
