11) x + 3y = 1
-3x – 3y =-15
Solve each system by substitution

X = -8 AND Y = 3

Step-by-step explanation:

from the question

let

x + 3y = 1   equation 1

-3x – 3y =-15 equation 2

from equation 1

x + 3y = 1   equation 1

by collecting the like terms

x = 1 - 3y equation 3

put x = 1 - 3y in equation 2

-3x – 3y =-15 equation 2

-3( 1- 3y)  - 3y = 15

-3 +9y  - 3y = 15

-3 + 6y = 15

6y = 15 + 3

6y = 18

divide both sides by 6

6y/6 = 18/6

y = 3

put y = 3 in equation  3

x = 1 - 3y equation 3

x = 1 - 3(3)

X = 1 - 9

X =-8

TEREFORE X = -8 AND Y = 3

answer: all the values are within because it has a pattern that repeats from -6 to 4.

good luck!