Question 328716
let width be x cm
length = x+9 cm

Area = 76 cm^2
Area = L*W
x(x+9)=76
x^2+9x=76
x^2+9x-76=0
find the roots of the equation  x1 x2
{{{x1=(-b+sqrt(b^2-4*a*c))/(2*a)}}}
{{{x1=(-9+sqrt(81-4*1*(-76)))/(2*1)}}} 
x1=5.311 cm width
{{{x2=(-9-sqrt(81-4*1*(-76)))/(2*1)}}}
=-14.31 cm ignore this value
length = 5.311+9=14.311 cm