150÷100=1.5
1.5×5=7.5
150+7.5= 157.5g
It's c.
for example:
2*2 +1 = 5
2*4 +1 =9
you can keep going ....
One pound is 16oz. So you take 54 and minus it by 16 until you get something less that 16. Then you take how many times you subtracted it, and that is how many pounds. Then you take the "leftover" number and they you have your answer.
so Sarita used 3 pounds and 8 oz.
Since x is the number of songs he has on his phone and if he adds 20 more, his expression will be: x+20