Answer
$\frac{5}{3}\approx 1.67,\ or, \ -\frac{2}{7}\approx -0.286$
Work Step by Step
For the equation $21x^2 -29x-10= 0$, we use the quadratic formula as follows
$$ x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}, \\
a=21, \quad b=-29, \quad c=-10.$$
That is,
$$ x=\frac{29 \pm \sqrt{29^2-4(21)(-10)}}{2(21) }=\frac{5}{3}\approx 1.67,\ or, \ -\frac{2}{7}\approx -0.286$$
