Mathematics · Oct / Nov 2020 · Paper 41 · Question 8
0580
As printed in the paper
Show the answer and mark scheme
8(a)[2]
ab(3a – b) final answer [2]
B1 for a(3ab – b2) or b(3a2 – ab) or ab(3a – b) seen
8(b)[2]
x > 7.5 final answer [2]
B1 for 12+3 < 5x – 3x oe
8(c)[2]
27x6y12 [2]
B1 for two of 27, x6 and y12 correct
8(d)[3]
0.5 or 1 2 [3]
M2 for 4 = 6x + 2x or better
or M1 for 2(2 – x) = 6x oe
8(e)[3]
2x3 + 5x2 – 23x + 10 final answer [3]
B2 for correct expansion of three brackets unsimplified
B1 for correct expansion of two brackets with at least 3 terms correct
8(f)(i)[3]
2 r 200 1 100 + = 206.46 oe 1 + 2 r + r 2 oe 100 2 100 r2 + 200r – 323 = 0 [3]
M1 M1 A1 Correct solution reached with no errors or omissions seen 2 If 0 scored,
SC1 for 200( ) n = 206.46
8(f)(ii)[3]
− 200 + 200 2 − 4(1)( 323) − 2 1 × 1.60 cao final answer [8]
B2 B1 for 200 2 − 4(1)( 323) − or (r + 100)2
B1 for 200 − + q or r = 323 + 100 2 – 100 2 1 × OR 206.46
B2 for 100 − 1 200 206.46
or B1 for 200 B1
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