標題:
(10分)中二數1題(不等式)
發問:
For two consecutive multiples of 3,5 times the larger number is not less than 2 times the smaller number plus 45. Find the minimum values of these two numbers. *Please show the famula and steps clearly.
最佳解答:
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Let the smaller # be x . so, the larger # is (x 3). 5(x 3) >2x 45 5x 15 >2x 45 5x-2x>45-15 3x > 30 x >10 because they are consecutive multiples of 3,the minimum value of the smaller # must be 12, and the mi-nimum value of the larger # is 12 3=15.
其他解答:
Let the larger number and the smaller number be (x+3) and x respectively. 5(x+3) > 2x+45 5x+15 >2x+45 3x > 30 x > 10 (because)They are consecutive multiples of 3. (so)The minimum value of the smaller number is 12, and the minimum value of the larger number is 12+3=15.