7m(4m=10)

Solution for 7m(4m=10) equation:

7m(4m=10)

We move all terms to the left:

7m(4m-(10))=0

We multiply parentheses

28m^2-70m=0

a = 28; b = -70; c = 0;
Δ = b2-4ac
Δ = -702-4·28·0
Δ = 4900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4900}=70$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-70)-70}{2*28}=\frac{0}{56}
=0
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-70)+70}{2*28}=\frac{140}{56}
=2+1/2
$