Simplify the expression 4^5 * 4^10. Write your answer using exponential notation

Tim's phone service charges $23.06 plus an additional $0.22 for each text message sent per month. if tim's phone bill was $28.56, which equation could be used to find how many text messages, x, tim sent last month?

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Molly shared a spool of ribbon with 12 people. each person received 3 feet of ribbon. which equation can she use to find r, the number of feet of ribbon that her spool originally had?