The answer would be B. All you would do is subtract 6.4 - 2.06 and you would annex a zero after the four. Then you would get 4.34
Answer:
D) b = 
Step-by-step explanation:
First, move all the terms that do not include b to the left side with S:
S = 2ab + 2bc + 2ac
S - 2ac = 2ab + 2bc
Now, factor out 2b from the right side:
S - 2ac = 2b(a + c)
Divide both sides by 2(a + c):
b = 
Finally, multiply out the denominator:
b = 
Set the two values equal to each other with 18x-2=12x+2 and then plug it in to the equation and solve
Answer:
50 envelopes for 2.49
Step-by-step explanation:
2.49/50= .05
5.50/90= .06
the first per is less than the 90 envelopes one therefore the answer is 50 for 2.49