Question 389241
If we use the quadratic formula,


{{{x = (-8 +- sqrt(64 - 4(15)))/-10 = (-8 +- 2)/-10}}} = 0.6 or 1, so 1 is the other x-intercept.


There's a simpler solution that doesn't involve the quadratic formula. If you know that the sum of the roots of the polynomial is -b/a = -8/-5 = 1.6, we have 1.6 = 0.6 + x, x = 1.