Maria had a square piece of paper. She cut 3 inches off the length and 4 inches off the width. Now the paper has a surface area of 30 in2. Which equation would you use to find the dimensions of the original piece of paper?

A. x2 - 7x + 12 = 0
B. x2 - 7x - 18 = 0
c. x2 - 3x - 4 = 30
D. x2 + 3x + 4 = 30

expand

(x-3)(x-4) = 30 and see which matches

evaluate r. 12Pr=1320

evaluate r. if12Pr=1320

To find the equation that represents the original dimensions of the square piece of paper, we need to work backward from the given information.

Let's assume that the original length of the paper was x inches. Since Maria cut 3 inches off the length, the new length would be x - 3 inches.

Similarly, assuming the original width of the paper was y inches, the new width would be y - 4 inches.

Now, we know that the surface area of the new piece of paper is 30 in². Since the paper is a square, the surface area can be calculated by multiplying the length by the width: (x - 3)(y - 4) = 30.

However, since the paper was originally a square, the length and width would be the same, so we can substitute y with x in the equation: (x - 3)(x - 4) = 30.

Expanding the equation, we get x² - 4x - 3x + 12 = 30, which simplifies to x² - 7x + 12 = 30.

Therefore, the equation that represents the dimensions of the original piece of paper is A. x² - 7x + 12 = 0.