Question 155230
r*t=d


Brenda __ r*t=30 __ t=30/r


Randy __ (r+5)(t+1)=60 __ substituting __ (r+5)((30/r)+1)=60 __ multiplying by r __ (r+5)(30+r)=60r


FOILing __ r^2+35r+150=60r __ subtracting 60r __ r^2-25r+150=0 __ factoring __ (r-15)(r-10)=0


r-15=0 __ r=15


r-10=0 __ r=10


there are two solutions
__ Brenda going 10 mph for 3 hr while Randy goes 15 mph for 4 hr
__ Brenda going 15 mph for 2 hr while Randy goes 20 mph for 3 hr