algebra
posted by Matt .
Word problems confuse me.
THe owner of a fancy food shoppe wants to mix cashews selling at $8/kg and pecans selling at $7/kg. How many kg of each kind of nuts should be mixted to get 8 kg worth $7.25/kg?

$8/kg*Xkg + $7kg*Ykg = 7.25/kg*8kg,
Eq1: 8X + 7Y = 58,
Eq2: X + Y = 8,
Multiply Eq2 by 8, add the 2 Eqs and get:
Y = 6,
Y = 6kgs of pecans.
Substitute 6 for Y in Eq2 :
X + 6 = 8,
X = 2 kgs of cashews.