Answer:
set mary is x years old, and helen is y years old.
first sentence:x=2y
second one:4(y-8)=x+4
bring x=2y in 4(y-8)=x+4
=>4y-32=2y+4
=>2y=36
=>y=18
=>x=36
mary:36
helen:18
Answer:
x = 25
Step-by-step explanation:
Given
x - 5 = 20 ( isolate x by adding 5 to both sides )
x = 25
Answer:
8/3
Step-by-step explanation:
<h3>
Answer: 5/9</h3>
As an approximate decimal, this is 0.5556 which converts to 55.56%
======================================================
Explanation:
Let's say there are 100 households (just for the sake of simplicity). We are told that 90% of them have answering machines. So that means 90 households have answering machines. In addition, 50 households have answering machines and call waiting. Those 50 households are part of the 90 mentioned previously.
We then select a house at random. Someone tells us (or we have some kind of prior knowledge) that whichever house is selected, they have an answering machine. We can ignore the 10 households that don't have an answering machine. Out of those 90 households, 50 have both features. So 50/90 = 5/9 is the probability of getting a household with both features.
The answer would be 1/2 or 50% if we didn't have the prior knowledge of the household having an answering machine. But with this prior knowledge, the conditions change and so does the probability.
----------------
You could also compute 0.50/0.90 to get the same answer.
We know that the midpoint is the a point in the center of the line (r). This means that from the midpoint to the endpoint (qr) is half the length of the overall line. This means that 5.7 (the length of qr) units is half the length of the line. Two halves make a whole so 5.7 × 2 = 11.4 units as the length of the entire line qs.
Hope this helps!
