When you add up the sum of the digits, it should be a multiple of three. 21 is 2 plus 1 equals 3, so since 3 is a multiple of three, 21 is divisible by 3
Answer:
Hence as long as x > 2/3, we can form a triangle from the three given sides.
Step-by-step explanation:
Given:
Length of 3 sides of triangle are 
Solution:
From the length of the 2nd side 4x, we know that x > 0
Let this be 1 st statement.
Now from the triangle inequality we can say that;

No new information from this because of the 1st statement above.
Also,

Lastly,

and again no new information is obtained from this inequality.
Hence as long as x > 2/3, we can form a triangle from the three given sides.
Answer:
2/5
Step-by-step explanation:
The slope of the line
y=2/5x-4
is 2/5 since it is in the form y = mx+b where m is the slope
Parallel lines have the same slope so a line that is parallel to y=2/5x-4 has a slope of 2/5
405=25n+80
405-80=325
325÷25=13
Answer: The answer is D, obtuse angles must be larger than 90 degrees