How do you write an equivalent expression by combining like terms

What properties allow transformation to be used as a problem solving tool

Marco has $38.43 dollars in his checking account. his checking account is linked to his amazon music account so he can buy music. the songs he purchases cost $1.29. part 1: write an expression to describe the amount of money in his checking account in relationship to the number of songs he purchases. part 2: describe what the variable represents in this situation.

Multiply. write your answer in simplest form. 3/8 x 5/7