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3 years ago

Prove that if xy > 0, then either x > 0 and y > 0 or x < 0 and y < 0

Mathematics

1 answer:

Rufina [12.5K]3 years ago

7 0

The rule of product states that:

$(+) \cdot (+) = (+)$
$(+) \cdot (-) = (-)$
$(-) \cdot (+) = (-)$
$(-) \cdot (-) = (+)$

So, a product is positive if and only if both factors have the same sign, and is negative if only if the factors have opposite sign.

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Amanda [17]

X=8
i learned this math class

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3 years ago

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Which expression is equivalent to −1/12−1/3

disa [49]

This equals to -5/12

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3 years ago

Help me please I need to do this

Blizzard [7]

Consider the attached tree.

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4 years ago

Marie has a small copy of rene magritte famous painting, The Schoolmaster. Her copy has dimensions 2 inches by 1.5.The scale of

klemol [59]

Ok so 1inch=40cm

2 inches by 1.5
multiply everybody by 40 and make them all centimeters
20*2=80
1.5*40=60

80cm by 60cm

1inch=2.54cm
find how many inches in 1 cm
divide both sides by 2.54
1/2.54inch=1cm

80 by 60 cm
multiply that by 1/2.54 nd find inches iquivlent

80 times 1/2.54=31.4960629921259842519685037008
60 times 1/2.54=23.622047...

ok so

dimentions is 31.4960629921259842519685037008 inches by 23.622047 inches

4 0

3 years ago

Read 2 more answers

Nola purchased two. 5 pounds of cheese for 10. $50 her mother purchased 3 pounds of the same cheese for $12.60 the cost of the c

Dovator [93]

Answer: 1 pound of cheese cost $4.2

Step-by-step explanation:

Nola purchased 2.5 pounds of cheese for 10. $50

Her mother purchased 3 pounds of the same cheese for $12.60

If the cost of the cheese varies directly with the number of pounds purchased, it means that the higher the pounds of cheese purchased, the higher the cost

To determine the the cost of 1 pound of cheese, we wound divide the the cheese by the number of pounds bought.

It becomes 10.5/2.5 = 4.2

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3 years ago