On the left side....Let's simplify under the radical, first
b^2 c
_____ - ___ multiplyy the second fraction by 4a on top and bottom
4a^2 a
b^2 4ac
____ - ____ and this gives us
4a^2 4a^2
[ b^2 - 4ac ]
__________ taking the square root of top and bottom we have
4a^2
√ [ b^2 - 4ac ]
____________
√ [ 4a^2 ]
√ [ b^2 - 4ac ]
____________
2a
So...combine tis with the first fraction on the left and we end up with
-b √ [ b^2 - 4ac ]
__ ± ____________ which gives us
2a 2a
-b ± √ [ b^2 - 4ac ]
________________ = [the right side ]
2a