HELP PLEASE

Using the quadratic formula gives:

$_{1,\:2}=\frac{-1\pm \sqrt{1^2-4\cdot \:7\left(-5\right)}}{2\cdot \:7}$

$x_1=\frac{-1+\sqrt{141}}{2\cdot \:7},\:x_2=\frac{-1-\sqrt{141}}{2\cdot \:7}$

$x=\frac{-1+\sqrt{141}}{14},\:x=\frac{-1-\sqrt{141}}{14}$

So if a and b are roots:

$(\frac{-1+\sqrt{141}}{14}-4)(\frac{-1-\sqrt{141}}{14}-4)$

(EDIT:  Just you are calc if you don't know how to solve!!!)

Just solve that and you got the answer 

-Vinculum

Expand: $(a-4)(b-4) = ab - 4a - 4b + 16 = ab - 4(a+b) + 16$

By Vieta's formula, we know that $ab = -{5 \over 7 }$ and $a+b = -{1 \over 7}$

Now, plugging this in, we get: $-{5 \over 7} -4(-{1 \over 7})+16 = {-{5 \over 7}} + { 4 \over 7}+16 = \color{brown}\boxed{15{ 6 \over 7 }}$

I completely forgot bout the Vieta's formula

I knew I did something wrong when I got those crazy numbers

Thanks, BuilderBoi 

I did?