Question

Where does the graph of y = 3x2 + 14x − 5 cross the x-axis?

(−5/3, 0) and (1, 0)

(5/3, 0) and (−1, 0)

(1/3, 0) and (−5, 0)

(-1/3, 0) and (5, 0)

Answer 1

Are you allowed to graph this?

Answer 2

no i can only choose an option

Answer 3

Do you know how to solve a quadratic equation using the quadratic formula?

Answer 4

the line cross x-axis when y=o. so substitute y=0 in the equation

Answer 5

it's c that is the root of equations that satisfies the above condition

Answer 6

@mathteacher1729 yes but im a little rusty because i havent been working on this for 2 weeks and i forgot the formula

Answer 7

@ghazi thanks a lot

Answer 8

anytime

Answer 9

@ghazi how was that in any way helpful beyond "giving the student the answer" ?

Answer 10

@cgossin123 If you're ever really stuck with a problem like this, you can also try substituting the x-coordinate into the equation and seeing if you get 0.

With fractions and and powers, it can get tricky, so make sure you're comfortable with manipulating fractions.

Answer 11

@mathteacher1729 well i wouldn't have given answer but this guy was in haste and by mistake i posted the answer...but i have given explanation with my answer...so as to make him clear