42z+56z^2-63=0

Solution for 42z+56z^2-63=0 equation:

42z+56z^2-63=0

a = 56; b = 42; c = -63;
Δ = b2-4ac
Δ = 422-4·56·(-63)
Δ = 15876
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{15876}=126$
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(42)-126}{2*56}=\frac{-168}{112}
=-1+1/2
$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(42)+126}{2*56}=\frac{84}{112}
=3/4
$