a college student earned $7800 during summer vacation working as a waiter in a popular restaurant.The student invested part of money at 10% and the rest at 9%.If the student received a total of $740 in interest at the end of the year,how much was invested at 10%

Question

amistre64 · Answer

ax +by = z; a = t-b

tx -bx +by = z

b(y-x) = z-tx

b@ y% = (z-tx)/(%-x)

amount@10% = (740/7800 - 7800(.09))/(.10 - .09)

amistre64 · Answer

i prolly missed that in teh z part ...

anonymous · Answer

not 4400    its 4200

amistre64 · Answer

amount@10% = (740 - 7800(.09))/(.10 - .09) maybe

amistre64 · Answer

3800@10% dbl chk

anonymous · Answer

i have 3800

amistre64 · Answer

3800(.10) + 4000(.09) ?= 740

380 + 360 ?= 740

740 = 740

anonymous · Answer

yeah ur right amistre....i did calculation wrong  !

anonymous · Answer

ok