Find the measures of angles 1,2,3

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

Sally deposited money into a savings account paying 4% simple interest per year.the first year,she earn $75 in interest.how much interest will she earn during the following year?

Which equation can be solved to find one of the missing side lengths in the triangle? cos(60o) = cos(60o) = cos(60o) = cos(60o) = mark this and return