Find a formula for an arithmetic sequence that begins 45, 40, 35, 30, ... a) qn = 40+5n
b) qn = 50-51
c) 9n = 45-5(n-5)
d) 9n=45-5n

If mary had 320 toy cars and she gave her friend 50 cars and then she gave her brother 72 more cars how much toy cars would mary have left ● explain with proper details