Math problems

Test Preparation ACT Preparation
1

On his fast day as a telemarketer, Marshall made 24 calls. His goal was to make 5 more calls on each successive day than he had made the day before. If Marshall met but did not exceed, his goal, how many calls had he made in all after spending exactly 20 days making callas as a telemarketer?
a 670
b 690
c 974
d 1430
e 1530

Is there an easier way to do this problem instead of going day by day

which of the following quadratic equations has solutions x=6a and x=-3b
x^2-18ab=0
x^2-x(3b-6a)-18ab=0
x^2-x(3b+6a)+18ab=0
x^2+x(3b-6a)-18ab=0
x^2+x(3b+6a)+18ab=0

2
  1. Do you mean "first" day?

Yes. Check out Gauss’s method:
http://nzmaths.co.nz/gauss-trick-staff-seminar

  1. In general, x = r is a solution of a polynomial iff x-r is a factor. The polynomial is of the form C(x-6a)(x-(-3b)) = C(x-6a)(x+3b). In our case C = 1 since the leading coefficient is 1. So just multiply (x-6a)(x+3b).
3

It’s an arithmetic sequence

4

This video will help you

https://www.khanacademy.org/math/algebra/sequences/introduction-to-arithmetic-squences/v/arithmetic-sequences