Standard +0.3 This is a straightforward absolute value inequality requiring the standard technique of squaring both sides (since both are positive) to eliminate the absolute values, then solving the resulting quadratic inequality. It's slightly above average difficulty due to requiring multiple algebraic steps and sign analysis, but remains a standard textbook exercise with no novel insight required.
Attempt solution of linear equation where 5x and 2x have
Answer
Marks
Guidance
different signs
M1
Or inequality.
Obtain 4
Answer
Marks
7
A1
State x10, x4
Answer
Marks
Guidance
3 7
A1
A0 if ‘… and …’ used.
Alternative Method for Question 1
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State or imply non-modulus equation (5x7)2 (2x3)2
(B1)
Or inequality.
Attempt solution of three-term quadratic equation
(M1)
Or inequality.
Obtain 10 and 4
Answer
Marks
3 7
(A1)
State x10, x4
Answer
Marks
Guidance
3 7
(A1)
A0 if ‘… and …’ used.
4
Answer
Marks
Guidance
Question
Answer
Marks
Question 1:
1 | Solve 5x72x3 to obtain 10
3 | B1 | Or inequality.
Attempt solution of linear equation where 5x and 2x have
different signs | M1 | Or inequality.
Obtain 4
7 | A1
State x10, x4
3 7 | A1 | A0 if ‘… and …’ used.
Alternative Method for Question 1
State or imply non-modulus equation (5x7)2 (2x3)2 | (B1) | Or inequality.
Attempt solution of three-term quadratic equation | (M1) | Or inequality.
Obtain 10 and 4
3 7 | (A1)
State x10, x4
3 7 | (A1) | A0 if ‘… and …’ used.
4
Question | Answer | Marks | Guidance