Answer:
18. [tex] 6xy + x - y + 12; x = 3, y = 5 [/tex]
[tex] 6(3)(5) + 3 - 5 + 12 [/tex]
[tex] 18(5) + 3 - 5 + 12 [/tex]
[tex] 90 - 2 + 12 [/tex]
[tex] 88 + 12 [/tex]
[tex] 100 [/tex]
19. let n be the number of voters
[tex] Given: 30n = 90,000 [/tex]
[tex] \frac{30n}{30} = \frac{90,000}{30} [/tex]
[tex] n = 3,000 [/tex]
20. let s be the number of sandwiches
[tex] Given: 7s - 16 = 264 [/tex]
[tex] 7s = 264 + 16 [/tex]
》addition property of equality
[tex] 7s = 280 [/tex]
[tex] \frac{7s}{7} = \frac{280}{7} [/tex]
[tex] s = 40 [/tex]
