Question

Help please hurry......

Juan has 20 books to sell. he sells the books for $15 each. The amount of money Juan makes from selling x books is represented by a function.
f(x)=15x
what is the practical range of the function?

all multiples of 15 between 0 and 300, inclusive

all multiples if 20 between 0 and 300, inclusive

all real numbers

all integers from 0 to 20, inclusive ​

Answer 1

All multiples of 15 between 0 and 300,inclusive

How?

`\\ \sf\longmapsto f(x)=15x`

`\\ \sf\longmapsto f(0)=15(0)=0`

`\\ \sf\longmapsto f(20)=15(20)=300`

Hence.

`\\ \sf\longmapsto 0\leqslant R_f\leqslant 300`