Please answer correctly

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

The number of potato chips in a bag is normally distributed with a mean of 71 and a standard deviation of 2. approximately what percent of bags contain between 69 and 73 potato chips? approximately 68% approximately 71% approximately 95% approximately 99.7%

Find the greatest common factor of -30x 4 yz 3 and 75x 4 z 2.