Can someone please answer number 8 for me?

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

Can someone me do math because i am having a breakdown rn because i don’t get it

Use the formulas a = x 2 – y 2, b = 2xy, c = x 2 + y 2 to answer this question. one leg of a right triangle has length 11 and all sides are whole numbers. find the lengths of the other two sides. the other leg = a0 and the hypotenuse = a1