Question

aflati termenul necunoscut x (x+13)+87=200

Answer 1

(x+13)+87=200
x+13=200-87
x+13=113
x=113-13
x=100

Answer 2

$(x+13)+87=200 \\ x+13+87=200 \\ x=200-13-87 \\ \boxed{x=100}$