Expanding two binomials
3 exam-style questions. Answers and the mark for each step are on the last page.
- Question 1
Expand and simplify each expression.
(a) Expand and simplify
(b) Expand and simplify
- Question 2
Expand and simplify each product.
(a) Expand and simplify .
(b) Expand and simplify .
- Question 3
A square has sides of length cm. A rectangle has length cm and width cm, where .
(a) Prove that the area of the square is always more than the area of the rectangle.
(b) The area of the rectangle is . Find the length of a side of the square.
Answers and marks
Question 1
(a)
- M1 At least three of the four terms correct: , , , .
- A1 .
(b)
- M1 At least three of the four terms correct: , , , .
- A1 The correct answer, .
Question 2
(a)
- M1 Write all four products before collecting like terms.
- A1 Correct answer:
(b)
- B1 Correct answer:
Question 3
(a)
- M1 Expanding the square's area to .
- M1 Expanding the rectangle's area to .
- C1 Subtracting correctly to get 16 and stating that it does not depend on .
(b) cm
- P1 Forming .
- P1 Solving to get (rejecting ).
- A1 The correct answer, cm.