Find the foci for the ellipse given by the equation: 9x^2 + 25y^2 = 225
a. (5, 0) and (-5, 0) c. (0, 3) and (0, -3) b. (4, 0) and (-4, 0) d. (0, 0) and (-1, 0)

you can first factor out the n to get n(1+5). we know that 1+5 is 6, so we just have 6n.

3boys + 4 girls = 7 students

3 boys to students   true   yes

4 girls to 3 boy   true     yes

3 boys to 7 girls   false   no

4 girls to 7 students   true   yes