Question #1Find the factors of -21 whenadded, it gives a sum of -20.
Answer (1)
Answer:y=1Step-by-step explanation:(x + y) = ( — 20), → x = ( — (20 + y)).(x * y) = ( — 21),Substitute ( — (20 + y)) for x, in (x * y) = ( — 21):(( — (20 + y)) * y) = ( — 21),( ( — (y^2)) — 20y ) = ( — 21),Rearranging into quadratic equation form:( (y^2) + 20y — 21 ) = 0,The factors of the constant term, — 21, when multiplied, and when added, give the linear term of + 20, are: — 1 and + 21,So,(y — 1)(y + 21) = 0, → Null Factor Rule:y = 1 OR y = — 21.
