Question

Given that the quadratic equation 3x^2+bx-2 has x-intercept {-2, 4}. What is the "b" value.

Please help ASAP I need the answer soon :(

Answer 1

The value of b is
`b=3`

Step-by-step explanation:

The given quadratic equation is
`y=3x^(2) +bx-2`

And has x - intercept
`(-2,4)`

To determine the value of b, let us substitute the coordinates
`(-2,4)` in the given quadratic equation
`y=3x^(2) +bx-2`

Substituting the x - intercept in the equation
`y=3x^(2) +bx-2`, we have,

`4=3(-2)^(2) +b(-2)-2`

Simplifying, we have,

`4=3(4)-2b-2`

`4=12-2b-2`

Adding the constant terms, we get,

`4=10-2b`

Subtracting both sides by 10, we have,

`-6=-2b`

Dividing both sides by -2, we get,

`b=3`

Hence, the value of b is
`b=3`