You have to know what it is before you solve the problem
Answer:
khan accademy will help you
Step-by-step explanation:
68 divided by 85 multiply by 100
68/85=0.8 x 100= 80%
88/8 =11
Unique key in 1 octave = 12
so, in 11 octave, 12*11 = 132
Step-by-step explanation:
We have y = 13 - 3x and y = 7 - x.
=> 13 - 3x = 7 - x
=> 2x = 6, x = 3.
Then y = 7 - (3), y = 4.
Hence the price of a pencil is $3 and the price of a notebook is $4. (C)