Answer:
c
Step-by-step explanation:
Two sum of any two side lengths of a triangle will always be greater than the length of the remaining side
a doesn't work because 8+12=20 and 20 is not greater than 20
b doesn't work because 4+5=9 and 9<10
d doesn't work because 6+6=12 and 12 is not greater than 12
c is the only option where you can take any two sides, add them, and the sum will be greater than the remaining side.
For example, for c,
6+8=14, and 14>10
8+10=18, and 18>6
10+6=16, and 16>8
The greatest common factor (GCF) of 9, 21 and 60 is: 3
Factors of 9: 1, 3, 9
Factors of 21: 1, 3, 7
Factors of 60: 1, 2, 3, 4, 5, 6
The common factors between the three numbers are 1 and 3, but since 3 is the highest number, it is considered the GCF.
Suppose

At the same time, we can write

Note that
(just reverse the sum). Let's pair the first terms of
and
, and the second, and the third, and so on:

Now, each grouped term in the sum on the right side adds to 151. There are 52 grouped terms on that same side (because there are 50 numbers in the range of integers 51-100, plus 50 and 101), which menas

But
, as we pointed out, so

Answer:
Step-by-step explanation:
2
x
2
+
8
−
4
x
+
3
x
−
6
x
2
+
7
Subtract
6
x
2
from
2
x
2
.
−
4
x
2
+
8
−
4
x
+
3
x
+
7
Add
8
and
7
.
−
4
x
2
−
4
x
+
3
x
+
15
Add
−
4
x
and
3
x
.
−
4
x
2
−
x
+
15
Answer: 60
Step-by-step explanation:
It’s an equilateral triangle based on the congruent sides.