One month, a homeowner used 150 units of gas and 520 units of electric for a cost of $84.20. The next month, 210 units of gas and 405 units of electric were used for a total cost of $82.35. Find the cost per unit of gas and electric.

One of the same side angles of two parallel lines is 20° smaller than the other one. find the measures of these two angles.

Write the expression 7x^3-28xy^2 as the product of 3 factors

Suppose you just purchased a digital music player and have put 8 tracks on it. after listening to them you decide that you like 4 of the songs. with the random feature on your player, each of the 8 songs is played once in random order. find the probability that among the first two songs played (a) you like both of them. would this be unusual? (b) you like neither of them. (c) you like exactly one of them. (d) redo () if a song can be replayed before all 8 songs are played.