Q6:
If x and k are integers and (12x)(42x+1) = (2k)(32), what is the value of k?
A. 5
B. 7
C. 10
D. 12
E. 14
我不明白怎么做这道题。答案是E
thanks
(12x)(42x+1) = (2k)(32)即4x3x42x4=(2k)(32),即22x+4x+23x=(2k)(32)
再比较一下等式两边可以得出:x=2; 6x+2=k, 所以答案是k=14
thanks.我忘了 12^x = (3^x) (4^X)
感激
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