Answer
$x\approx 0.24$ and $x\approx -4.24$.
Work Step by Step
The given equation is
$\Rightarrow -5x^2-20x+35=30$
Subtract $35$ from each side.
$\Rightarrow -5x^2-20x+35-35=30-35$
Simplify.
$\Rightarrow -5x^2-20x=-5$
Divide each side by $-5$.
$\Rightarrow x^2+4x=1$
Find the value of $(\frac{b}{2})^2$.
Substitute $4$ for $b$.
$=(\frac{4}{2})^2$
Simplify.
$=(2)^2$
$=4$
Add $4$ to each side of the equation.
$\Rightarrow x^2+4x+4=1+4$
Simplify.
$\Rightarrow x^2+4x+4=5$
Write the left side as the square of a binomial.
$\Rightarrow (x+2)^2=5$
Take the square root of each side.
$\Rightarrow x+2=\pm \sqrt{5}$
Subtract $2$ from each side.
$\Rightarrow x+2-2=\pm\sqrt{5}-2$
Simplify.
$\Rightarrow x=\pm\sqrt{5}-2$
The solutions are $x=\sqrt{5}-2\approx 0.24$ and $x=-\sqrt{5}-2\approx -4.24$.
