So you can use
$21.95 + $.19x = $18.95 + $.21x
Answer:
Is the answer, if you want it simplified then, 
Step-by-step explanation:
Answer:
450+70x
Step-by-step explanation:
x is the number of months and 450 is the actual amount of money in his bank account
Well, since a is Susan’s current age, we would add three to a to get her age in three years
So our expression would be:
a + 3