1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
sveta [45]
3 years ago
15

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.

You might be interested in
HELP WITH ANY OR ALL THESE PROBLEMS ASAP PLEASE LIKE NOW PLEASE<br>CAN SOMEONE PLEASE HELP 
LiRa [457]

Ques 8:

The Volume(V) in cubic feet of an aquarium id modeled by the polynomial function V(x)= x^{3}+2x^{2}-13x+10

a) We have to explain that why x =4 is not a possible rational zero.

By Factor theorem, which states that a polynomial f(x) has a factor (x - k) if and only if f(k)=0.

For this , we will substitute the value of x in the given function.

V(x)=x^{3}+2x^{2}-13x+10

V(4)=4^{3}+2(4)^{2}-13(4)+10

V(4)=4^{3}+2(4)^{2}-13(4)+10

V(4)=54 which is not equal to zero.

Therefore, x=4 is not a possible rational zero.

(b) To show that (x-1) is a factor of V(x).

By Factor theorem, which states that a polynomial f(x) has a factor (x - k) if and only if f(k)=0.

Let (x-1)=0

So, x=1.

Substituting x=1 in the given function.

V(1)=1^{3}+2(1)^{2}-13(1)+10

V(1)= -10+10

V(1) = 0

Therefore, (x-1) is a factor of V(x).

Now we will factorize the given function.

Dividing the given function by (x-1).

On dividing, we get quotient as x^{2}+3x-10

So, factored form is = (x-1)(x^{2}+3x-10)

= (x-1)(x^{2}+5x-2x-10)

= (x-1)(x(x+5)-2(x+5))

=(x-1)(x+5)(x-2)

(c) So, the dimensions are 1,2 and -5.

5 0
3 years ago
Which graph decreases, crosses the y-axis at (0,-7) and then remains constant?​
Bumek [7]

Answer: Graph A

Step-by-step explanation: The line drops, crosses over the y axis, then stays at that constant level

6 0
3 years ago
Read 2 more answers
Which equation represents the function shown in the input-output table?
stepladder [879]

Answer:

Equation B

Step-by-step explanation:

Equation B because:

it is 7x + 3

so for the first one, it's 7 + 3

the second one is 14 + 3

the third one is 21 + 3

the fourth one is 28 + 3

Please Mark Brainliest

4 0
3 years ago
A. A polynomial of the 5th degree with a leading coefficient of 3 and a constant of 2.
loris [4]
3x^5 + 2
The ^ sign means the number after it is an exponent.
8 0
3 years ago
Write an equation of the line perpendicular to the given line that contains P.
Shalnov [3]

Answer:

Step-by-step explanation:

perp. -5

y + 7 = -5(x - 4)

y + 7 = -5x + 20

y = -5x + 13

8 0
3 years ago
Other questions:
  • Classify the expression: 5x + 3x2 − 7x3 + 2.
    9·2 answers
  • What is 3 feet less than the Legnth <br> three less than the length
    12·1 answer
  • Greater than (-3) but less than or equal to 3
    14·2 answers
  • Which ones are linear and nonlinear?<br><br>NEED ASAP <br>RIGHT ANSWER WILL GET MARKED AS BRAINLIEST
    14·1 answer
  • X^2+x-6 plz tell this
    7·2 answers
  • Drag the tiles to the correct boxes to complete the pairs. Not all tiles will be used.
    13·1 answer
  • Help me it’s due today
    15·1 answer
  • Work out the median for each data set.
    9·1 answer
  • Please Help solve simultaneous equations , I never got hang of it.
    9·2 answers
  • A<br> D<br> P<br> 55°<br> С<br> (5x-35)°<br> B<br> What is the value of x?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!