Question

2x + 5y = 145 x + y = 50

Answer 1

For this, you've got to double one of the equations, and this will then allow you to eliminate part of the equation.$2x+5y= 145 \\ 2x+2y=100. \\ 5y-2y= 145-100 \\ 3y=45 \\ y=15$
As you've now got one part, you've got to substitute this in, and this gives you;
$2x+5*15= 145 \\ 5*15=75 \\ 145-75= 70 \\ 2x=70 \\ x=35$
$x+1*15=50 \\ 50-15= 35 \\ x=35$
Once you've done both equations, you have to ensure that they're correct, and in this case, they are.
Therefore, <u />$y=15 \\ x=35$
Hope this helps :)