Answer: x represents the number of months, 150 represents one-time materials fee, 2( 21x + 75 ) represents total fees in x months and 42 represents rate of change.
Explanation:
Since, Here the expression 2( 21x + 75 ) represents the monthly tuition and the one-time materials fee that Jamie pays for his two children to join a science club.
Let, f(x) represents the monthly tuition fee
Therefore, f(x)= 2( 21x + 75 )
⇒f(x)= 42 x +150
Again according to the question, there is a one-time materials fee which must be free from the variable.
Therefore In f(x) , 150 must represent one time material fees.
And, x is variable, and here number of months is a variable.
Thus, x must be denote the number of months.
And, 42 must be denote the fees for 1 month.