help asap im in a quiz, please show some sort of proof. and please dont say,¨ the answer is in the photo

step-by-step explanation:

is their an equation anywhere i can take a   look at it and see if i am right.

the answer would be a 24

step-by-step explanation:

c=2πr=2·π·3=24

system of linear equation

step-by-step explanation:

as given in the data

a= 20 , b= -12

let us suppose that it is a straight line equation

now we know the formula for the system of linear equation

b= ma + c )

here m is slope of a straight line which is equal to formula

m=   (ii)

and here c is a constant

now putting the value of a and b in equation (ii)

m=

m=

putting the value of a,b and m in equation (i) gives us

-12 = + c

-12=-12 + c

adding 12 to both sides

-12 +12 = -12 +12 +c

0 =c

or c=0

as the value of the constant is zero which gives us that it is a linear equation and this order pair satisfies the system of linear equations.