Answer:
x = 600 Tn first variety
y = 800 Tn second variety
Explanation:
Let call " x " the delivered quantity of the first wheat variety
and " y " the delivered quantity of the second wheat variety
Then x + y = 1400 (ton)
and 0,02*x + 0.03*y = (1400 - 1364) ⇒ 0,02*x + 0.03*y = 36
So we get a two equations system
x + y = 1400
0.02*x + 0.03*y = 36
Solving for x and y
y = 1400 - x
0.02*x + 0.03 ( 1400 - x ) = 36
0.02*x + 42 - 0,03*x = 36
- 0.01*x = - 6 ⇒ x = 6/ 0,01 ⇒ x = 600 Tn
and y = 1400 - 600 ⇒ y = 800 Tn