Its a square.
So 5n = n + 16
Therefore 4n = 16 (taking one n from each side).
So n = 16/4 which is simplied as : 4.
Double check by putting 4 in the equation where n is, and it makes sense, so that is the right answer.
Your answer is c.
Y = cos(x)
sqrt(3)/2 = cos(30º)
dy = -sin(x)*dx
dy = -sin(30º)*(pi/180) = (1/2)*(pi/180)
y + dy = cos(x) - sin(x)dx
y + dy = sqrt(3)/2 - (1/2)*(pi/180) = 0.8573
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1 1/2 cups = 3/2. 3/2 divided by 4 = 3/2 x 1/4 = 3/8 cup