The capacities at which U. S. nuclear power plants are working are shown in table for various years. Year Percent
1975 56
1980 59
1985 58
1990 70
1995 76
2000 88
2004 89

Let
f
(
t
)
be the capacity (in percent) at which U. S. nuclear power plants are working at t years since 1970. A model of the situation is
f
(
t
)
=
0.027
t
2
+
0.216
t
+
53.296
.

Efficient homemakers ltd. makes canvas wallets and leather wallets as part of a money-making project. for the canvas wallets, they need two yards of canvas and two yards of leather. for the leather wallets, they need four yards of leather and three yards of canvas. their production unit has purchased 44 yards of leather and 40 yards of canvas. let x be the number of leather wallets and y be the number of canvas wallets. draw the graph showing the feasible region to represent the number of the leather and canvas wallets that can be produced.