N4=c
n times 4, n being a number of notebooks, would equal c, or the overall cost.
Answer:
Length = 90 inch.
width = 30 inch
Let width of the rectangle = x inch.
So the length = 3x inch.
Perimeter = 2(length + width) = 2 (3x + x) = 8x.
So,
length = 3x = 3(30) = 90 inch.
width = x = 30 inch
15 square feet because the scale is 2 in:1 ft so it would be 10/2 which is 5. This means the flag is 5 ft x 3 ft aka 15 square feet
X^2+x-12=0 factors out into (x+4)(x-3) so the answer is: x=-4, x=3