This is the concept of algebra, to solve the expression we proceed as follows;
cos 2x-cosx=0
cos 2x=cosx
but:
cos 2x+1=2(cos^2x)
thereore;
from:
cos 2x=cos x
adding 1 on both sides we get:
cos 2x+1=cos x+1
2(cos^2x)=cosx+1
suppose;
cos x=a
thus;
2a^2=a+1
a^2-1/2a-1/2=0
solving the above quadratic we get:
a=-0.5 and a=1
when a=-0.5
cosx=-0.5
x=120=2/3π
when x=1
cos x=1
x=0
the answer is:
x=0 or x=2/3π
Ans. 1 Angle E and angle F are corresponding angles.
Solution 2.
So,
angle E = angle F
=> x + 20 = 5x - 20
=> x + 20 + 20 = 5x
=> x + 40 = 5x
=> 40 = 5x - x
=> 40 = 4x
=> 40/4 = x
=> 10 = x
Solution 3.
E = x + 20
=> E = 10 + 20
=> E = 30
F = 5x - 20
=> F = 5(10) - 20
=> F = 50 - 20
=> F = 30
<em>Again</em><em> </em><em>justified</em><em> </em><em>that </em><em>they </em><em>are </em><em>equal</em><em> (</em><em> </em><em>besides</em><em> </em><em>answer </em><em>1</em><em>)</em><em>.</em>
Answer:
(x,y) = (0,0)
Step-by-step explanation:
Let both as equation (1) and (2)
put equal both sides -x = -7x
-x + 7x = 0
6x = 0
x = 0
put it in 2nd equation
y = -7(0)
y = 0
Company 1 average= 24.4 minutes
company 2 average= 19.8 minutes
company 3 average= 15 minutes
company 4 average= 19 minutes
The answer is 24.4 or company one
let the speed of plane in still air be x and that wind be y
therefore:
x+y=490
x-y=390
next we solve for the values of x and y, first we add the above equations. This will give us:
2x=880
x=880/2
x=440 miles per hour.
substituting the value of x in one of the equations and solving for y we get:
440+y=490
y=490-440
y=50 miles per hour
