The diagram shows a small rectangle inside a large rectangle. The height of the large rectangle is x cm. The length of the large rectangle is 4 times its height. The width of the shaded border is 3 cm. The area of the small rectangle is 80 cm². [Figure Rectangles with Border]
- (a)Form an equation in x and show that it simplifies to 2x² - 15x - 22 = 0.[4]
- (b)Solve the equation 2x²-15x-22 = 0 . Show your working and give your answers correct to 2 decimal places.[3]
- (c)Calculate the shaded area.[2]
This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.
Mark scheme
Marking points from the official mark scheme (Oct/Nov 2023). The mark or mark type is shown in brackets.
- [4] M2 B1 for x-6 or 4x-6 seen
- B1 for 4x x x - 80 oe
- M1 FT expansion of (4x – c)(x – d)
- FT dep on a maximum of one omission or a numerical error in previous equation
- A1 A0 if any errors or omissions
- [3] B2 for -(-15)±√(-15)²-4×2×-22 / (2×2) oe
- B1 for (-15)²-4x2x-22 oe
- or for -(-15)±√their discriminant / (2×2) oe
- B1 -1.26 and 8.76
- [2] M1 for (their 8.76)×(4×their 8.76)-80 oe
- or 30×their 8.76-36 oe
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →