42p2-85p+42=0

Solution for 42p2-85p+42=0 equation:

42p^2-85p+42=0

a = 42; b = -85; c = +42;
Δ = b2-4ac
Δ = -852-4·42·42
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-85)-13}{2*42}=\frac{72}{84}
=6/7
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-85)+13}{2*42}=\frac{98}{84}
=1+1/6
$