O-LevelMathematicsAlgebra and graphs4024/21 · Oct/Nov 2023 · Q711 Marks

Simplify. 7a-4b-2a+b

(a)Simplify. 7a-4b-2a+b[2]
(b)Expand and simplify. 3 (2x-3) + 5 (x+2)[2]
(c)Solve. 6x²-2x-9= 0 Show all your working and give your answers correct to 2 decimal places.[3]
(d)(i)Write as a single fraction in its simplest form. x/4 ÷ 2/y[1]
(d)(ii)Write as a single fraction in its simplest form. 3/(x-5) - 7/(2x+1)[3]

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2023). The mark or mark type is shown in brackets.

[2] (a) 5a-3b final answer
[2] (a) B1 for answer 5a+kb or ka-3b k≠0 or for 5a-3b seen
[2] (b) 11x+1 final answer
[2] (b) B1 for answer 11x+k or kx+1 k≠0 or M1 for 6x-9+5x+10 seen
[3] (c) -(-2)±sqrt((-2)^2-4x6x-9)/(2x6) oe or -(-2)±sqrt(their discriminant)/(2x6) or for (x+-2/(2x6)) and sqrt(-2^2-4x6x-9) / (2x6) (oe) B2
[3] (c) B1 for (-2)^2-4x6x-9 oe
[3] (c) M1 for quadratic formula with one error
[3] (c) -1.07 and 1.40 B1
[1] (d)(i) xy/8 final answer
[3] (d)(ii) (38-x)/((2x+1)(x-5)) or (38-x)/(2x^2-9x-5) final answer
[3] (d)(ii) B1 for 3(2x+1)-7(x-5) oe isw
[3] (d)(ii) B1 for denominator (2x+1)(x-5) oe isw

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