Algebra
posted by mysterychicken .
2. A long distance phone company has a monthly fee of $7.95 and charges a rate of $0.05 per minute. Another long distance company has a monthly fee of $9.95 and charges a rate of $0.03 per minute. At how many minutes would the two companies have equal charges?
15. A boat travels 30 miles upstream in 4 hours. The trip downstream takes 2.5 hours. Find the rate of the boat in still water.
20. Solve: 5x^2  10x = 0
50. (x1)(x^3 + x^2 + x) =?
Thanks
MC

2. C1=C2 7.95+.05X=9.95+.03X
.05X.03X=9.957.95
X=100 Minutes
CI=Cost at 1st company
C2=Cost at 2nd company 
15. Rate upstream=30/4=7.5m/hr
Rate downstream=30/2.5=12m/hr
Rate in stillwater=(7.5+12)/2=9.75m/hr 
50. (x1)(x^3+x^2+x)=x^4+x^3+x^2x^3x^2x=x^4x=x(x^31)