(I don't know this, I googled the problem and it opened the answer on openstudy, so I copied and pasted it to here)
ok...
they say that the total Sue expects from her crops is = $8500
and
she gets $1050 per acre from apples...
if she grows "a" acres then her outcome will be
1050a
she gets $2500 per acre from pecans
if she grows "p" acres then the outcome will be
2500p
but since her total is 8500
1050a + 2500p = 8500 ----(1)
21a + 50p = 170 -----(1)
since her land area is 15 acres
a + p = 15 ----(2)
so.. ur choices will contain one out of the followings..
hope this will help ya :)