a- one number
b- second number
a + b = 43 (the sum of two numbers is 43)
(a +11) = b (he larger number is 11 more than the smaller number)
so:
a + b = 43
a + (a + 11) = 43
a + a + 11 = 43
2a = 43 - 11
2a = 32
a = 16
now:
a + b = 43
16 + b = 43
b = 43 - 16
b = 27
that is:
a = 16
b = 27
--------------------------
checking:
b - a = 11
27 - 16 = 11 (TRUE)