Someone me i’ll mark as brainliest

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

Scott harris can invest $7,000 in a 1-year cd that earns interest at an annual rate of 4 percent compounded monthly. the amount per $1.00 is 1.040742. he can also invest $7,000 in a 1-year cd at annual rate of 4 percent compounded quarterly. the amount per $1.00 is 1.040604. what is the difference in the amount of interest earned for each investment? a) $0.96 b) $0.81 c) $0.87 d) $0.88

Add the fractions and simplify 1/2+ 1/3