Question

What are the y and x intercepts for -2x^2 + 7x -3
For the y intercept I got (0, -3)
But for the x intercepts using the general quad formula I could not get an answer as I cant square a negative. Not sure what I'm doing wrong - could someone give it a go please.

Answer 1

y=-2x^2 + 7x -3
for x intercept put y=0
-2x^2 + 7x -3 =0
-2x^2 + 6x+x -3=0
(x-3)*(-2x+1)=0
x=3 or 1/2
y intercept put x=0
y=-3

Answer 2

Thanks for the reply but I'm not sure what you are doing here. How do you get from -2x^2 + 7x -3 =0 to -2x^2 + 6x+x -3=0

Answer 3

@dehelloo
x=3&1/3
y=-3.
wet get this by putting x=0(for y-intercept& y=0(for x-intercept).

Answer 4

Yep I understand that we have to turn x to = for the y intercept and y into 0 for the x int. I am just not sure what to do after that.

Answer 5

he has split the middle term into 2 parts that can be factored...

-2x^2 + 6x + x - 3 = 0

factor each pair or terms

-2x^2 + 6x has common factors of -2x

so you get

-2x(x - 3) + 1(x -3) = 0

now you have a common factor of (x -3)

so you end up with

(x -3)(-2x + 1) = 0

so you now have the binomial factors of the quadratic...

just solve each binomial... for the x intercepts

hope this makes sense

Answer 6

so you now need to find the values of x that make either binomial equal to zero

so you are solving

x - 3 = 0

and

-2x + 1 = 0

so when y = 0 x will equal your solutions

Answer 7

How does he split the middle term into 2 parts.

Answer 8

Where does he get the extra x from and how does the 7 change into a 6.

Answer 9

hi guys