Chapter 1 - Review Exercises - Page 145: 45

See below.

Let $x$ be the amount she invests in A-rated bonds and then $70000-x$ is the amount invested in CDs, then our equation is: $1.08x+(70000-x)1.05=70000+5000\\1.08x+73500-1.05x=75000\\0.03x=1500\\x=50000$ So $50000$ should be the amount she invests in A-rated bonds and then $20000$ is the amount invested in CDs.