Higher January 2021 Paper 1 Q5
5
(a) Factorise fully \(15y^4 + 20uy^3\) (2)
(b) Solve \(4 - 3x = \dfrac{5 - 8x}{4}\)
Show clear algebraic working. (3)
Show clear algebraic working. (3)
| Scheme | Marks |
|---|---|
| \(5y^3(3y + 4u)\) | B2 |
| (2) |
Notes
B2: for \(5y^3(3y + 4u)\)
(B1 for \(5y(3y^3 + 4uy^2)\)
or \(5y^2(3y^2 + 4uy)\)
or \(y^2(15y^2 + 20uy)\)
or \(y^3(15y + 20u)\)
or \(5y^3(\ldots)\) where there is only one mistake in the brackets)
| Scheme | Marks |
|---|---|
\(4 \times (4 - 3x) = 5 - 8x\) oe or \(16 - 12x = 5 - 8x\) oe or \(4 - 3x = \dfrac{5}{4} - 2x\) oe | M1 |
e.g. \(16 - 5 = 12x - 8x\) or \(11 = 4x\) oe or \(4 - \dfrac{5}{4} = 3x - 2x\) | M1 |
| Working required Answer: 2.75 | A1 |
| (3) | |
| (5 marks) |
Notes
M1: for removal of fraction in a correct equation
M1: for terms in \(x\) on one side and numbers on the other side in an equation, allow correct rearrangement of their equation in the form \(ax + b = cx + d\)
A1: (dep on M1) oe e.g. \(2\dfrac{3}{4}\) or \(\dfrac{11}{4}\)