To calculate percentage, we turn the percentage into a decimal.
30% of 30 = 0.3 of 30 = 0.3 x 10
0.3 x 10 = 3
3 students play in the school band.
You do the sum backwards,
36-16=17
17x3=51
Then you check it to make sure,
51/3=17
17+19=36
:) hope this hepled x
If $26 represents the cost of the 5 used CDs, than your formula would be "26+4x" ,x being the amount of extra CDs you purchase.
The number CDs minus 5 is our x value, because the first 5 are the used CDs bundled into the $26 group.
26+4(6-5)
26+4(1)
26+4
30
6 CDs would cost $30