so don't know the equation but it's 15 months. a year and 3 months.
Step-by-step explanation:
so first able, he already has 150 in his saving account. he adds 25$ every month after hai bday. a year has 12 months in which one of them is his birthday. so the rest 11 months he adds 25$. 25×11=275 then 150+275=425 so he needs 75 more dollars to have 500$ 25+25+25=75 so there fore we have 3 more months. so that means that a year and three months. sorry if you didn't understand I'm bad at explaining
