0.7x(8x+16)=1.8(x+2)

Solution for 0.7x(8x+16)=1.8(x+2) equation:

0.7x(8x+16)=1.8(x+2)

We move all terms to the left:

0.7x(8x+16)-(1.8(x+2))=0

We multiply parentheses

0x^2+0x-(1.8(x+2))=0


We calculate terms in parentheses: -(1.8(x+2)), so:

1.8(x+2)

We multiply parentheses

1.8x+3.6

Back to the equation:

-(1.8x+3.6)


We add all the numbers together, and all the variables

x^2+x-(1.8x+3.6)=0

We get rid of parentheses

x^2+x-1.8x-3.6=0

We add all the numbers together, and all the variables

x^2-0.8x-3.6=0

a = 1; b = -0.8; c = -3.6;
Δ = b2-4ac
Δ = -0.82-4·1·(-3.6)
Δ = 15.04
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{-(-0.8)-\sqrt{15.04}}{2*1}=\frac{0.8-\sqrt{15.04}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.8)+\sqrt{15.04}}{2*1}=\frac{0.8+\sqrt{15.04}}{2}
$