Guys please help me!! :(

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

Aline has a slope of and a y-intercept of –2. what is the x-intercept of the line?

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.