Stacey has $20,000 to invest, split between an account paying 3% and one paying 5%, and wants a blended rate of 4.5%. How much should she invest at 3%?

1. Let x equal the amount invested at 3%, so 20,000 minus x is invested at 5%. 2. The interest equation is 0.03x plus 0.05(20,000 minus x) equals 0.045 times 20,000, or 900. 3. Distribute and combine like terms: negative 0.02x plus 1,000 equals 900. 4. Subtract 1,000 and divide by negative 0.02 to get x equals 5,000. 5. Stacey should invest $5,000 at 3% and the remaining $15,000 at 5%. _Source: OpenStax Elementary Algebra (CC BY 4.0), Ch 3 "Math Models", section 3.3 Solve Mixture Applications_