Question

Solve

13x + 11y = 70

11x + 13y = 74

• A. x = 2 and y = 4
• B. x = -2 and y = -4
• C. x = 2 and y = 6
• D. x = 3 and y = 4

Answer 1

The correct option is A

x = 2 and y = 4

Given equations : 13x + 11y = 70 and 11x + 13y = 74

Here the coefficient of x in the first equation is equal to the coefficient of y in the second equation and the coefficient of y in the first equation is equal to the coefficient of x in the second equation.

Adding the two given equations we get

24x + 24y = 144 $\Rightarrow$ x + y = 6.......(i)

Subtracting the two given equations we get

2x - 2y = -4 $\Rightarrow$ x - y = -2.......(ii)

Now solving (i) and (ii) we get

x = 2 and y = 4