Answer:
x = -3 2/3
Explanation:
Given the simultaneous equations;
3 x + 7 y = 31 ..... 1
-3x - 2y = -1 ..... 2
Add both expressions
7y - 2y = 31-1
5y = 30
y = 30/5
y = 6
Substitute y = 6 into equation 2
From 2;
-3x - 2y = -1
-3x - 2(6) = -1
-3x - 12 = -1
-3x = -1 + 12
-3x = 11
x = -11/3
x = -3 2/3
Hence the value of x is -3 2/3