D(x)=-3/5x+17

Solution for D(x)=-3/5x+17 equation:

(D)=-3/5D+17

We move all terms to the left:

(D)-(-3/5D+17)=0


Domain of the equation: 5D+17)!=0

D∈R


We get rid of parentheses

D+3/5D-17=0

We multiply all the terms by the denominator


D*5D-17*5D+3=0

Wy multiply elements

5D^2-85D+3=0

a = 5; b = -85; c = +3;
Δ = b2-4ac
Δ = -852-4·5·3
Δ = 7165
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$D_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$D_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$D_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-85)-\sqrt{7165}}{2*5}=\frac{85-\sqrt{7165}}{10}
$
$D_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-85)+\sqrt{7165}}{2*5}=\frac{85+\sqrt{7165}}{10}
$