So if these are simultaneous equations here are the steps:
Bring the variables to one side and the constants to the other side of the equal sign. Remember if you bring anything to the other side it’s sign has to change:
x + y = 12
2x + 3y = 29
Now multiply a variable on the top equation so that it will be equal with the variable on the second:
3x + 3y = 36
2x + 3y = 29
Now subtract the equations which gets you:
x = 7
So we know what the x is, now we have to substitute the x in an equation we created; we’ll go with x + y = 12:
x + y = 12
= 7 + y = 12
Now bring the variable to one side and constants to the other like we did before (remember, the sign must change if the constant or variable is moved to different sides of the equal sign):
y = 12 - 7, which would equal y = 5.
So our answer would be:
( x, y ) = ( 7, 5 )
Hope this helps have an awesome day!