Answer:
9 days
Step-by-step explanation:
He sets his watch 12 seconds behind
For every day that passes it falls back another 1 second
So once it is 21 seconds behind all you have to do is subtraction to find the amount of days past
21 - 12 = 9
Since its 12 seconds behind already itll take 9 days to be behind 9 more seconds.
Area of rectangular board = length (inches) x width (inches) = 12" x 16" = 192 in²
Area of the border is given as 128 in²
Adding the area of the board and the border gives (192 + 128)in² = 320 in²
Set this up as the algebraic equation (x + 12)(x + 16) = 320 and solve for x:
Remember to use the FOIL method, which is multiplying the terms in the order of first, outer, inner, last.
x² + 12x + 16x + 192 = 320
x² + 28x + 192 - 320 = 0
x² + 28x - 128 = 0
solve for the two x values:
(x + 32)(x - 4) = 0, and knowing we only need the positive x value
x = 4 or 4 inches is the width of the border
x= +7 or x=2-7 let me know if you need an explanation <3
9% decrease because 145-132=13
13=9% of 145
