3m^2-14m-42=7

Solution for 3m^2-14m-42=7 equation:

3m^2-14m-42=7

We move all terms to the left:

3m^2-14m-42-(7)=0

We add all the numbers together, and all the variables

3m^2-14m-49=0

a = 3; b = -14; c = -49;
Δ = b2-4ac
Δ = -142-4·3·(-49)
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-28}{2*3}=\frac{-14}{6}
=-2+1/3
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+28}{2*3}=\frac{42}{6}
=7
$