R = { (x,y): 3x-y=0 }
The condition is 3x=y so that's not going to be any of these things.
R is reflexive if (x,x)∈R for all x. Let's check.
3x - y = 3x - x = 2x ≠ 0 necessarily. NOT REFLEXIVE
R is symmetric if (x,y)∈R → (y,x)∈R. Let's check.
(x,y)∈R so
3x-y = 0
y = 3x
Is (y,x)∈R. That would be true if 3y-x=0
3y - x = 3(3x) - x = 8x ≠ 0 necessarily NOT SYMMETRIC
R is transitive if (x,y)∈R and (y,z)∈R → (x,z)∈R. Let's check.
3x-y = 0 so y=3x
3y-z = 0 so z=3y = 9x
3x - z = 3x - 9x = -6x ≠ 0 necessarily NOT TRANSITIVE
The perimeter is 47cm. The area would be 111cm^2. Hope this helped, could I possibly get brainliest?
Answer:she will have 60 dollars left because 5 times 4 is 20 and if she sold them for 3 dollars you just do 20 times 3 and you should get 60
Step-by-step explanation:
Answer:
Area: 40
Step-by-step explanation:
To find the area of a parallelogram you multiply the base times the height, or the length times the height. This is why you multiply 5x8 to get 40. The substitution could be 5 x 8 = X
X is the area.
Answer:
Step-by-step explanation:
In order to add or subtract numbers in scientific notation, the powers of ten must have the same exponent. In this caes the diameter of an average human body cell is a power of -4 and the diameter of a plant cell is a power of -3. In order to add them, we can move the decimal over for the body cell diameter:
Add the two values: 
