let the numbers be x and y
x + y = 1600 ----*
12%x = 20%y
0.12x = 0.2y
y = <u>0</u><u>.</u><u>1</u><u>2</u><u>x</u>
0.2
y = 0.6x
substitute in * eqn
x + 0.6x = 1600
1.6x = 1600
x = 1000
then,
y = 0.6*1000
y = 600
the numbers are 1000 and 600
Compound percentage reduction can be calculated by multiplying the initial number by (1-x)^t where x is the percentage reduction (/100, i.e. 1% reduction is 0.01), and t is the number of times it has reduced.
So:
a)

Where t is the number of weeks.
We can then just substitute in to work out the final pressure:
b) p = 45*0.94^6 =
31psi
Translation 1 unit left and rotation of 90 degrees counterclockwise
First set up the equation:

Then substitute in known values:

and solve for C

Our goal is to get y by itself
We will first add 3x to both sides to get
-5y = 3x - 15
We will then divide both sides by -5 to get y by itself which becomes
y = -3/5x + 3