To solve a quadratic equation ax^2 + bx + c = 0, wecan use the quadratic formula above given on the Regents Reference Sheet.

In order to find out if a solution is rational or irrational, we focus on the algebra under the radical: b^2 – 4ac: If b^2 – 4ac is a perfect square, then when we take the square root, we will get a rational number but if b^2 – 4ac is not a perfect square (like 4, 9, 16 etc), then the solution will be irrational.

In the equation 2x^2 + 3x – 10 =0, a=2, b=3 and c = -10

Once you substitute in those numbers into b^2 – 4ac, do you get a perfect square or not?