Higher January 2019 Paper 2R Q10

EdexcelHigherCurrent spec7 marksManipulating Formulae/ Changing the Subject Solving Simple Equations

(a) Simplify fully \(\left(16x^8y^6\right)^{\frac{1}{2}}\) (2)

(b) Solve \(\dfrac{8 - 2x}{3} - \dfrac{2x - 3}{2} = 4\)
Show clear algebraic working. (3)

Scheme	Marks
\(4x^4y^3\)	B2
	(2)

Mark scheme (b)

Scheme	Marks
e.g. \(2(8 - 2x) - 3(2x - 3) = 4 \times 6\) or \(\dfrac{2(8 - 2x)}{6} - \dfrac{3(2x - 3)}{6} = 4\) or \(\dfrac{16 - 4x}{6} - \dfrac{6x - 9}{6} = 4\) or \(\dfrac{2(8 - 2x) - 3(2x - 3)}{6} = 4\) or \(\dfrac{-10x + 25}{6} = 4\) oe	M1
e.g. \(16 - 4x - 6x + 9 = 24\) or \(-10x + 25 = 24\) oe	M1
0.1	A1
	(3)

Notes

M1: For method to deal with fractions

eg. finds a common denominator (6 or a multiple of 6)

or

multiplies by common multiple in a correct equation.

Condone one error in expansion

M1: For method to expand brackets and multiplies by common denominator in a correct equation.

Condone one error in expansion

A1: oe dep on M1

Scheme	Marks
\(m^2 = \dfrac{1}{3}ef\)	M1
\(f = \dfrac{3m^2}{e}\)	A1
	(2)
	(7 marks)