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One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.

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