Question

1.11. a)
y = x - 1,
x + 3y = 9;​

Answer 1

y=x-1

x+3y=9

y=x-1

x+3(x-1)=9

x+3x-3=9

4x=9+3

4x=12

x=3

y=x-1

x=3

y=3-1

x=3

y=2

x=3

(3;2)