This is my third time posting this question, which is my fault. my teacher does not want me to use substitution rules.

using rules of inference and no substitution, prove that:

–p +-q) + (pλq)

and:

(5l + d) + (byd)

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0

Barbara has a good credit history and is able to purchase a car with a low-interest car loan. she co-signs a car loan for her friend jen, who has poor credit history. then, jen defaults on the loan. who will be held legally responsible by the finance company and why? select the best answer from the choices provided. a. barbara will be held legally responsible because she has a good credit history. b. jen will be held legally responsible because she drives the car. c. barbara will be held legally responsible because she is the co-signer. d. jen will be held legally responsible because she has a poor credit history. the answer is a