Answer:
m = 
Step-by-step explanation:
distribute parenthesis on both sides
ac + am = 2c + 6m ( collect terms in m on left side )
subtract 6m from both sides
ac + am - 6m = 2c ( subtract ac from both sides )
am - 6m = 2c - ac ( factor left side )
m(a - 6) = 2c - ac ( divide both sides by (a - 6))
m = 
She spent 20 dollars on each book because if you subtract 18 from 198 you'll get 180 then you divide that by 9 n it leaves you with 20.
The answer is no solution
There are 4 boys and 12 students in total. It would be 4/12, but if it was to be simplified, it would be 1/3. The probability of a boy being selected is 1/3.