The formula N = 2Xsquared + 22X + 320 represents the number of inmates, N, in thousands, in U.S. state and federal prisons x years after 1980. According to the formula, in what year were there 740 thousand inmates in the U.S. state and federal prisons?
2x^2 + 22x + 320 = 740
2x^2 + 22x - 420 = 0
x^2 + 11x - 210 = 0
(x - 10)(x + 21)
10 years
The formula N = 2Xsquared + 22X + 320 represents the number of inmates, N, in thousands, in U.S. state and federal prisons x years after 1980. According to the formula, in what year were there 740 thousand inmates in the U.S. state and federal prisons?
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