✔ 最佳答案
(a) x/(x^2 + 6x + 8) = √576/(x + 2).
x/[(x + 2) * (x + 4)] = 24/(x + 2) <--- (*)Set: x + 2 ≠ 0 ---> x ≠ -2, and x + 4 ≠ 0 ---> x ≠ -4.
Multiply both sides by [(x + 2) * (x + 4)].
[(x + 2) * (x + 4)] * x/[(x + 2) * (x + 4)] = [(x + 2) * (x + 4)] * 24/(x + 2).
---> x = 24(x + 4).
x = 24x + 96.
x - 24x = 96.
-23x = 96.
x = -96/23 (Feasible solution, according to the solution set of the equation).
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(b) 2x^2 + 7x + 6 = 0 <--- Use the quadratic formula in order to find the roots.
x = [-7 ± √(49 - 48)]/4 = (-7 ± 1)/4.
Either: x = (-7 - 1)/4 = -8/4 = -2 (Answer).
Or: x = (-7 + 1)/4 = -6/4 = -3/2 (Answer).
The only correct choice in your list is a) (Answer).