Easy -1.2 This is a straightforward application of the binomial theorem requiring identification of the term where powers of x cancel to give x^(-1). It's a standard textbook exercise with a single technique and minimal steps, making it easier than average but not trivial since students must correctly handle negative powers.
Use correct method for finding x from a positive root
M1
Obtain answer x = 0.638 and no other answer
A1
Total:
5
Question
Answer
Marks
Question 2:
2 | State or imply u2 =u+5, or equivalent in 5x | B1
Solve for u, or 5x | M1
1
Obtain root (1+ 21), or decimal in [2.79, 2.80]
2 | A1
Use correct method for finding x from a positive root | M1
Obtain answer x = 0.638 and no other answer | A1
Total: | 5
Question | Answer | Marks