4x^2+3x^2=700

Solution for 4x^2+3x^2=700 equation:

4x^2+3x^2=700

We move all terms to the left:

4x^2+3x^2-(700)=0

We add all the numbers together, and all the variables

7x^2-700=0

a = 7; b = 0; c = -700;
Δ = b2-4ac
Δ = 02-4·7·(-700)
Δ = 19600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{19600}=140$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-140}{2*7}=\frac{-140}{14}
=-10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+140}{2*7}=\frac{140}{14}
=10
$