X/3 +2y/3= -1 and x-y/3=9 solve. by elimination method

X=51/7, Y= -36/7

Step-by-step explanation:

X/3 + 2y/3 = -1 equ 1

X - y/3 = 9 equ 2

eliminate X/3.

X/3 + 2y/3 = -1 x 1 ( co-efficient of X in equ2 )

X - y/3 = 9 x 1/3 ( co-efficient of X in equ1 )

X/3 + 2y/3 = - 1 equ 3

-

X/3 - y/9 = 3 equ 4

0 + 7y/9 = -4

y = -36/7

( input the value of y into equ 4 )

X/3 -y/9 = 3

X/3 - (-36/7)/9 = 3

X/3 + 36/63 = 3

X/3 = 3 - 36/63

X/3 = 153/63

63X = 459

X = 459/63

X = 51/7.

the answer for the second equation is (4,0)

arc length = radius * x ( in radians)

6 * pi = 18 * x

divide by 18 on each side

6 pi / 18 = x

pi/3 = x

the angle is pi / 3 radians

or   60 degrees