Multiply bottom equation by -3 to add and eliminate y’s.
So...
5x-15y=10
+-9x+15y=18
You get -4x=28 so x=-7
Plug in to get y
5(-7)-15y=10
-35-15y=10
-15y=45
So y=-3
Check in other equation
3(-7)-5(-3)=
-21+15=-6
So x= -7 and y= -3
First, let's identify some variables:
d = dress price
s = shirt price
d = 3s
12s + d = 450
Because d = 3s, we can substitute the variable:
12s + 3s = 450
15s = 450
s = 30
The shirt costs $30, and the dress $10
C = 2πR ⇒ R = C/2π = 12/2π = 6/π ≈ 6/3,14 = 600/314 ≈ 1.91
