What is it a ,b, c,or d can i get a step by step explanation

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer

The lengths of all sides of a triangle are integers when measured in decimeters. one of the sides has length of 1 dm and another of 3 dm. find the perimeter of the triangle.'

Venita is sewing new curtains. the table below shows the relationship between the number of stitches in a row and the length ofthe row.sewingnumber of stitches length (cm)51 131532024306what is the relationship between the number of stitches and the length? othe number of stitches istimes the length.o. the number of stitches is 3 times the length.