A woman seeks to invest no more than $20,000 of her savings in municipal bonds and mutual funds. The amount she will invest in municipal bonds will be at least three times the amount she will invest in mutual funds. However, she will invest no more than $5,000 in mutual funds. Under her constraints, which graph below indicates the possible ways the woman can invest her savings?
The constraints are:
(1) b > 0; f > 0 (i.e., no negative dollar values)
(2) b + f ≤ 20000 (i.e., total investment will be no more than $20,000)
(3) b ≥ 3f (i.e., the amount invested in municipal bonds will be at least three times that in mutual funds)
(4) f ≤ 5000 (i.e., no more than $5,000 invested in mutual funds)
Can someone show me how to graph these constraints?