N=12-2 is the answer of this question
18 shells because since Mary has 6 and Tina has 3 shells all you have to do is multiply 6 and 3 to get 18
5x + 4y = 32 ⇒ 45x + 36y = 288
9x - 1y = 33 ⇒ <u>45x - 5y = 165</u>
<u>41y</u> = <u>123</u>
41 41
y = 3
5x + 4(3) = 32
5x + 12 = 32
<u> - 12 - 12</u>
<u>5x</u> = <u>20</u>
5 5
x = 4
(x, y) = (4, 3)
-5x + y = -5.....multiply by -2
-4x + 2y = 2
---------------
10x - 2y = 10 (result of multiplying by -2)
-4x + 2y = 2
-----------------add
6x = 12
x = 12/6
x = 2
-5x + y = -5
-5(2) + y = -5
-10 + y = -5
y = -5 + 10
y = 5
solution is (2,5)
It i 104 oz
Hope This Helps
