Answer:
1) (x, y) = (1, 8)
2) (x, y) =(-2, -4)
3) (x, y) = (3, -1)
Explanation:
1) Given the equations;
7x+2y =23 .... 1
6x+y= 14 .... 2
From 2; y = 14-6x
Substitute into 1;
From 1; 7x+2y =23
7x + 2(14-6x) = 23
7x + 28 - 12x = 23
-5x = 23 - 28
-5x = -5
x = 5/5
x = 1
Substitute x = 1 into y = 14-6x
y = 14 - 6 (1)
y - 14 - 6
y = 8
Hence (x, y) = (1, 8)
2) Given
y=-4
y=-3x-10
We will simply equate bith expression and get x;
-3x - 10 = -4
-3x = -4 + 10
-3x = 6
x = 6/-3
x = -2
Hence the solution is (-2, -4)
3) Given the equation
y=-3x+8
y=5x-16
Equate both expressions;
-3x + 8 = 5x - 16
-3x - 5x = -16 - 8
-8x = -24
x = 24/8
x = 3
Substitute x = 3 into y=-3x+8
y = -3(3) + 8
y = -9 + 8
y = -1
Hence the solution (x, y) = (3, -1)