Abank wishes to invest a $100, 000 trust fund in three sources: bonds paying 8%; certificates of deposit paying 7%; and first mortgages paying 10%. the bank wishes to realize an $8, 000, annual income from the investment. a condition of the trust is that the total amount invested in bonds and certificates of deposit must be triple the amount invested in mortgages. how much should the bank invest in each possible category? hint: denote x, y and z the amounts invested in bonds, certificates of deposit, and first mortgages, respectively; and solve the corresponding linear system by using the inverse method