Question 291103
When they say "by substituion", that means take isolate one variable in a sentence, and substitute that variable into the other equation.  In this case, the first statement already has establish a value for x (namely 2+y), so we substitute (2+y) for x, into the second statement, and solve for y:

4(2+y) - 3y = 11
8 + 4y = 3y = 11; now, subtract 8 from both sides
4y = 3y + 3; now, subtract 3y from both sides
{{{highlight(y = 3)}}}.

Substitute the y=3 back into the first statement:

x = 2 + 3
{{{highlight(x = 5)}}}

Verify, by substituting into original equations:
5 = 2 + 3.  OK

4(5) - 3(3) = 11
20 - 9 = 11.  OK.