3x+0.05(x+0.10)x=7.50

Solution for 3x+0.05(x+0.10)x=7.50 equation:

3x+0.05(x+0.10)x=7.50

We move all terms to the left:

3x+0.05(x+0.10)x-(7.50)=0

We add all the numbers together, and all the variables

3x+0.05(x+0.1)x-(7.5)=0

We add all the numbers together, and all the variables

3x+0.05(x+0.1)x-7.5=0

We multiply parentheses

0x^2+3x+0x-7.5=0

We add all the numbers together, and all the variables

x^2+4x-7.5=0

a = 1; b = 4; c = -7.5;
Δ = b2-4ac
Δ = 42-4·1·(-7.5)
Δ = 46
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-\sqrt{46}}{2*1}=\frac{-4-\sqrt{46}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+\sqrt{46}}{2*1}=\frac{-4+\sqrt{46}}{2}
$