Last year, Evelin's invested 10,000 dollars, part at 6% annual interest, and the rest at 8% annual interest. If she recieves $760 at the end of the year, how much did he invest at each rate?

X - The part invests in 6%

10,000 - X -- The rest invests in 8 %

X ( 0.06) --gain in 6% investment

(10,000 - X ) 0.08 -- gain on 8%

Solve for X , if:

X ( 0.06 ) + ( 10,000 - X ) ( 0.08) = 760

X ( 0.06) - X ( 0.08 ) = -10,000( 0.08) + 760

X ( - 0.02 ) = - -800 + 760 = -40

X = -40/ -0.02 = 2,000 / invested in 6% Plan

10,000 - 2,000 = 8,000 / invested in 8% plan