{х+у=11 {(100х+10у+3)-(10х+у)831

To solve the first equation, х + у = 11, we can use the method of substitution or elimination. Let's use substitution.

From the first equation, we have х = 11 - у.

Now we substitute this value of х into the second equation:

(100х + 10у + 3) - (10х + у) = 831

Simplifying the equation:

100(11 - у) + 10у + 3 - 10(11 - у) - у = 831

Now we solve for у:

1100 - 100у + 10у + 3 - 110 + 10у - у = 831

Combining like terms:

-90у - 108 + 20у - у = 831 - 1100 + 110

Simplifying the equation:

-71у - 108 = -159

To isolate у, we add 108 to both sides:

-71у = -51

Dividing both sides by -71:

у = -51 / -71

у = 51 / 71

Now that we have the value of у, we can substitute it back into the first equation to find the value of х:

х + у = 11

х + 51 / 71 = 11

Multiplying both sides by 71:

71х + 51 = 781

Subtracting 51 from both sides:

71х = 730

Dividing both sides by 71:

х = 730 / 71

Therefore, х ≈ 10.28 and у ≈ 0.72.