If 2x + 5y = 8 and 3x = 2y, what is the value of 2x + y?A、4B、70/19C、64/19D、56

游客2025-02-27  5

问题 If 2x + 5y = 8 and 3x = 2y, what is the value of 2x + y?

选项 A、4
B、70/19
C、64/19
D、56/19
E、40/19

答案 D

解析 From 3x = 2y, it follows that y = 3x/2, so 8 = 2x + 5(3x/2)=19x/2. Then x = 16/19, 2x = 32/19, and y =24/19.
Thus 2x + y =56/19 .     
The correct answer is D.
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