Aaron is 1 year younger than Laura
Their combined age is 23
Let
Aaron = A
Laura = L
A = L - 1
A + L = 23
Plug in "L - 1" for "A"
(L - 1) + L = 23
Simplify, combine like terms
L - 1 + L = 23
2L - 1 = 23
isolate the L, add 1 to both sides
2L - 1 (+1) = 23 (+1)
2L = 24
Divide 2 from both sides to isolate the L
2L/2 = 24/2
L = 24/2
L = 12
Laura is 12 years old
Plug in 12 for L in one of the equations
A = L - 1
A = (12) - 1
A = 11
Aaron is 11 years old
hope this helps