<u><em>subsitution</em></u> means subsituteing something for another and getting the answer
the way to do this is to get an easy equation and make it equal to only one placeholder so
y=2x
so you can subsitute y for 2x anywhere you see a y
3x+y=5
subsitutute
3x+2x=5
5x=5
divide both sides by 5
x=1
subsitute
y=2(1)
y=2
<u><em>elimination</em></u> is when you elimintate one of the terms by adding the equations together and canceling som of them out
so y=2x
subtract y from both sides
0=2x-y or 2x-y=0
add this to the second equation
3x+2x+y-y=0+5
5x=5
divide both sides by 5
x=1
subsitute
y=2(1)
y=2
x=1
y=2
If you divide your y factor by your x factor on each one then round you should get 2.2 or round to 2.2! hope that helped
Cos45 = cos(2*22.5) = (cos22.5)^2 - (sin22.5)^2 = (cos22.5)^2 * (1-(tan22.5)^2)
= (1 + cos45)/2 * (1-(tan22.5)^2)
Now, solve for tan22.5:
tan22.5 = sqrt(1 - 2cos45 / (1+cos45) )
Speed: 30mi/sec
Seconds in one minute: 60
Seconds in 6 minute: 60 x 6 = 360 seconds
take the speed of 30miles / seconds and times it with 360, and you get a total distant traveled: 10800 miles