Answer:
he added the dimensions of the rectangle. He used the wrong formula. the formula he used was length + breadth. He should have multiplied by 2
6x + 8y +8
Step-by-step explanation:
Perimeter of a rectangle = 2 x (L + B)
L = length
b = breadth
2 (3x + 4y + 4. ) = 6x + 8y +8
Answer:
Step-by-step explanation:

Y = 12x......y = 12(4).....y = 48.....so she pays $ 48 for the old brand when buying 4 boxes
y = 8x...y = 8(4)......y = 32...so she pays $ 32 for the brand she changed to, when buying 4 boxes
so the super saving brand would save her (48 - 32) = $ 16 per month
It i 104 oz
Hope This Helps