Word Problem: Arlene wishes to invest $5000. If she invests part at 7% simple interest, part at 6%, and receives a total of $332 after one year, how much does she invest at each rate?

Question

amistre64 · Answer

seven@7% = (332 - 5000(.06))/(.07 -.06)

amistre64 · Answer

id say 3200 @ 7% and the rest at 6%

amistre64 · Answer

a + b  =  t;  find an equation for all the money split into 2 parts

ax + by = z; determine an equation that accounts for the percents
                        and the total amount at the end

now eliminate one of the parts


a + b  =  t; *-x
ax + by = z




-ax -bx  = -tx
  ax+by  = z
-------------
     b(y-x) = (z -tx)

  b@y = (z-tx)/(y-x)