Answer:
B
Step-by-step explanation:
In a triangle, the sum of any two sides must be bigger than the third.
For the first one, 10+20=30 is not greater than 30, so this is not correct.
For B, 122+137 = 259 > 257, 257+137>122 , and 257 + 122 > 137. This works
For C, 8.6 + 2.7 = 11.3 < 12.2, so this does not work
For D, 1/6 + 1/5 = 5/(6*5) + 6/(6*5) = 5/30 + 6/30 = 11/30 < 1/2 = 15/30, so this does not work
Answer:4
Step-by-step explanation: 3x+1−2x=2x+5−2x
x + 1 = 5
x+1−1=5−1
x=4
Answer:
f (x) = a(x - h)2 + k, where (h, k) is the vertex of the parabola.
Step-by-step explanation:
I’m trying to figure this out too
Answer: 
Step-by-step explanation:
The common ratio is 15/3 = 5.
The first term is 3.
So, the explicit rule is 