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Prove that if a is a natural number, then there exist two unequal natural numbers k and l for which ak−al is divisible by 10.
2 answers:
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A) Since neither inequality includes the "or equal to" case, the boundary line for the solution set is a dashed line. For the first inequality, the shading is above the line; for the second, the shading is below the line. The solution set is points to the right of perpendicular lines with slope -2 and +1/2 through point (2, -1).
B) The point -2, 3 satisfies, neither inequality.
.. 3 > -2(-2) +3 . . . FALSE
.. 3 < 1/2(-2) -2 . . .FALSE
A) Since neither inequality includes the "or equal to" case, the boundary line for the solution set is a dashed line. For the first inequality, the shading is above the line; for the second, the shading is below the line. The solution set is points to the right of perpendicular lines with slope -2 and +1/2 through point (2, -1).
B) The point -2, 3 satisfies, neither inequality.
.. 3 > -2(-2) +3 . . . FALSE
.. 3 < 1/2(-2) -2 . . .FALSE