Answer:
The life expectancy of a circulating coin is 25 years. The life expectancy of a circulating dollar bill is only 1/20 as long.
Step-by-step explanation:
Answer:
The values are
x = -25/9 = -2 7/9
y = 7/3 = 2 1/3
Step-by-step explanation:
3x + 2y = -13 --------eqn 1
3x + 4y = 1-------------eqn2
Using eqn 2 to get the value of y
3x + 4y = 1
4y = 1 - 3x
Dividing both sides by 4,to get y
4y/4 =( 1 -3x) / 4
y = (1 - 3x) / 4
Since we've gotten the value for y, substitute the value into eqn 1
3x + 2y = -13
3x + 2(3x - 1)/4 = -13
Opening the bracket
3x + (6x - 2)/4 = -13
LCM = 4
(12x + 6x - 2) / 4 = -13
18x - 2 / 4 = -13
Then we cross multiply
18x - 2 = -13 * 4
18x - 2 = - 52
18x = -52 + 2
18x = -50
Divide both sides by 18, to get the value of x
18x/18 = -50/18
x = -25/9
or x = -2 7/9
The value of x is now known, so let's go back to eqn 2
Substitute x = - 25/9
3x + 4y = 1
3(-25/9) + 4y = 1
Open the bracket
-75/9 + 4y = 1
Make y the subject of the formula
4y = 1 + 75/9
LCM = 9
4y = (9 + 75)/ 9
4y = 84/9
To get y, divide both sides by 4
4y/4 = 84/9 / 4/1
y =
Note : when division changes to multiplication, it always be in its reciprocal form
y = 84/9 / 1/4
y = 84 * 1 / 9 *4
y = 84/ 36
y = 7/3
Or
y = 2 1/3
Answer:
Yes
Step-by-step explanation:
1) Cos 300 = Cos (360 - 60) = Cos 60 {Cos 360 - theta = Cos theta}
= 1/2
Sin 300 = Sin (360 - 60) = -Sin 60 = 
3) 3π/4 = 3*180/4 = 135
Cos 135 = Cos (90 + 45) = -Cos 45 = 
Sin 135 = Sin (90 + 45) = Sin 45 = 
Tan=sin/cos
So sin a= 7
Cos a= 24
