Prove that 1/a + 1/c = 2/b if X=y=zº and y² = xz

Why do interests rates on loans to be lower in a weak economy than in a strong one

An electrician cuts a 136 foot long piece of cable. one piece is 16 feet less than 3 times the length of the other piece. find the length of each piece

Ashley recently opened a store that sells only natural ingredients. she wants to advertise her products by distributing bags of samples in her neighborhood. it takes one person 22 minutes to prepare one bag. how many hours will it take to prepare 900900 bags of samples if ashley and 55 of her friends do the work?