How do you solve #5[9-x(x+8)]=5x(1-x)#?

1 Answer
Oct 8, 2015

Simplify both sides and then use standard methods to obtain:
#color(white)("XXX")x=1#

Explanation:

#color(red)(5[9-x(x+8)]) = color(blue)(5x(1-x))#

#color(red)(5[9-x^2-8x]) = color(blue)(5x-5x^2)#

#color(red)(-5x^2-40x+45) = color(blue)(-5x^2+5x)#

#color(white)("XXX")-40x+45 = 5x#

#color(white)("XXX")x=1#