Answer:C=2πr=2·π·2≈12.56637in
Step-by-step explanation:
So in this case, we have to replace the known value.
y=3
y=-2x+3
3=-2x+3
Then we leave our unknown value alone.

= x
In this case, our x value would be 0.
We check it...
3=-2(0)+3
3=0+3
3=3
So y=3 x=0
For the second one we have...
y=3x+2
y=-3x-4
For this we substitute the y in any of the equation...
3x+2=-3x-4
We move the unknown values to one side and the ones without unlown values to the other side...
3x+3x=-4-2
Then we solve
6x=-6
Then we leave the unknown value alone.
x=

Then solve for x.
x= -1
Then for our y value we return to one of the original equations and substitute the x value.
y=3x+2
y=3(-1)+2
y=-3+2
y=-1
y=-3x-4
y=-3(-1)-4
y=3-4
y=-1
So in this case we got that x= -1 and y= -1
Answer: 14x^2-93xy+60y^2 Hope that helps!
Step-by-step explanation:
1. Expand by distributing terms
(20x-12y)(x-4y)-(3x-4y)(2x+3y)
2. Use the Foil method:(a+b)(c+d)= ac+ad+bc+bd
20x^2-80xy-12yx+48y^2-(3x-4y)(2x+3y)
3. Use the Foil method : (a+b)(c+d)= ac+ad+bc+bd
20x^2-80xy-12yx+48y^2-(6x^2+9xy-8yx-12y^2)
4. Remove parentheses 20x^2-80xy-12yx+48y^2-6x^2-9xy+ 8yx+12y^2
5. Collect like terms (20x^2-6x^2)+(-80xy-12xy-9xy+8xy)+(48y^2+12y^2)
6. Simplify.
And your answer would be 14x^2-93xy+60y^2
The answer would be 30.
60/2 = 30
90/2 = 45
120/2 = 60