Question and choices are in the photo please explain the answer

What is r i 4.5+10r=-6.5 with work pls

If x-1 and x+3 are the factors of x3+10x2+ax+b find a and b

Will’s boss has asked him to compile the credit scores of everyone in his department. the data that will collected is shown in the table below. what is the mode of the credit scores in will’s department? (round to the nearest whole point, if applicable.) 634 667 644 892 627 821 857 703 654 a. 667 b. 722 c. 627 d. there is no mode in this group.