1) 3xy + 4y^3
x = 5
y = 2
3 (5)(2) + 4 (2)^3
30 + 4 (8)
30 + 32
answer: 64
2) 3c - 15 = 90
add 15 on both sides
3c = 105
divide by 3 on both sides
c = 105/3
c = 35
answer: $35
3) s × (100+9.3÷100)
s × (109.3÷100)
s ×1.093
[tex]decimal \: multiplier \: for \: percentages \\ \frac{100 + - \%\%\ }{100} [/tex]
answer: 1.093s
