Library / / 57 of 310
, 2012 Difficulty 1.3 Junior Find the answer Canada
If x = 2 x=2 x = 2 v = 3 x v=3x v = 3 x ( 2 v − 5 ) − ( 2 x − 5 ) (2v-5)-(2x-5) ( 2 v − 5 ) − ( 2 x − 5 )
Pick one
A 2 2 2 B 8 8 8 C − 2 -2 − 2 D − 7 -7 − 7 E 6 6 6
Solution Since v = 3 x v=3x v = 3 x x = 2 x=2 x = 2 v = 3 ⋅ 2 = 6 v=3\cdot 2 = 6 v = 3 ⋅ 2 = 6
Therefore, ( 2 v − 5 ) − ( 2 x − 5 ) = ( 2 ⋅ 6 − 5 ) − ( 2 ⋅ 2 − 5 ) = 7 − ( − 1 ) = 8 (2v-5)-(2x-5) = (2\cdot 6 - 5) - (2\cdot 2 - 5) = 7 - (-1) = 8 ( 2 v − 5 ) − ( 2 x − 5 ) = ( 2 ⋅ 6 − 5 ) − ( 2 ⋅ 2 − 5 ) = 7 − ( − 1 ) = 8
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