John earns $2050 earnings from his part-time job and makes an investment at the bank in two parts. One part is invested at 7%/a (per annum or year) and the rest at 6%/a. After 1 year the investments
earned $128 of interest.

How much money was invested at 6%/a?

a) y = -3x +2

b) y = 1/2x -6

these 2 can be combined into one equation.

-3x +2 = .5x -6

8 = 3.5x

x = 8 / 3.5 = 2.2857142857

y = -3 * (8 / 3.5) +2

y = (-24 / 3.5) + 2

y = -4.8571428571

step-by-step explanation:

investment b is an ordinary annuity with $3,909.64 in the account after one year.

step-by-step explanation: