Answer:

Step-by-step explanation:
Let the number be x.
Translating the word problem into an algebraic equation, we have;
Opening the bracket, we have;

Collecting like terms, we have;

9514 1404 393
Answer:
x = 10 2/3
Step-by-step explanation:
The ratios of corresponding sides are the same, so we have ...
x/8 = 8/6
x = 8·(8/6) = 64/6
x = 10 2/3
This revolves around exact trig values - no easy way to say this, you just need to memorise them. They are there for sin cos and tan, but I will give you the main tan ones below - note this is RADIANS (always work in them when you can, everything is better):
tan0: 0
tanpi/6: 1/sqrt(3)
tanpi/4: 1
tanpi/3: sqrt(3)
tanpi/2: undefined
Now we just need to equate -2pi/3 to something we understand. 2pi/3 is 1/3 of the way round a circle, so -2pi/3 is 1/3 of the way round the circle going backwards (anticlockwise), so on a diagram we already know it's in the third quadrant of the circle (somewhere between pi and 3pi/2 rads).
We also know it is pi/3 away from pi, so we are looking at sqrt(3) or -sqrt(3) because of those exact values.
Now we just need to work out if it's positive or negative. You can look up a graph of tan and it'll show that the graph intercepts y at (0,0) and has a period of pi rads. Therefore between pi and 3pi/2 rads, the values of tan are positive. Therefore, this gives us our answer of sqrt(3).
Let
be the number of days spent at Tahoe and San Francisco, respectively.
We don't know the values of
and
yet, but we know that the holiday lasted 9 days:

We also know that each day spent in Tahoe costed 350 and each day spent in San Francisco costed 475. So, the total cost of the holiday is the sum of the number of days muliplied by their cost:

If we put the two equations together, we have the system

Which yields

7.5%
how to do it
to dived 600 m by 8000m and get .075 to switch it to % you multiply it by 100 geting 7.5%