It has 1 solution and it is 1.6. to find this answer take 2.25 and subtract it from 3.5 you get 1.25z and -4.25+6.25 is 2. not you have 1.25z=2. divide 2 by 1.25 which is 1.6 and you get your z value. hope I helped! hope you understand this. please mark me as brainliest if you appreciate my answer to help me rank up!