Hello, Alex.
Okay, so he bought 5 postcards at $.55/ ea. so that would be 5 x .55.
He also bought a set of postcards for $1.20.
So the expression to find the amount he spent on all the postcards would be:
(5 x 0.55) + 1.20 =
2.75 + 1.20 = 3.95
Therefore, he spent $ 3.95 on the postcards