# Making up an Equation That Satisfies Given Conditions

#### Joystar1977

##### Active member
Make up an equation that satisfies the given conditions: must have x-intercepts at (-1, 0) and (2, 0). It must also have a y-intercept at (0, 4).

Is it correct to say that the equation with x-intercepts would look like this:

y = (x - 2) (x + 1)

How do you factor the y-intercept?

#### MarkFL

Staff member
Re: Making up an Equation Satisfies Given Conditions

Make up an equation that satisfies the given conditions: must have x-intercepts at (-1, 0) and (2, 0). It must also have a y-intercept at (0, 4).

Is it correct to say that the equation with x-intercepts would look like this:

y = (x - 2) (x + 1)

How do you factor the y-intercept?
You are definitely on the right track. I would use the form:

$$\displaystyle y=k(x-2)(x+1)$$

Now let $y=4$ and $x=0$ and solve for $k$.