Algebra 7
4 marks · NormalConsider the quadratic equation , where is a constant.
Complete the following table by factorising the equation for each given value of , and listing the roots.
| k | Factorised form | Roots |
|---|---|---|
| 5 | ||
| -7 |
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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Must show: Correct factorised form and both roots for each k
Common mistakes: Incorrect factorisation or wrong sign for roots
Show mark scheme and worked solution
Marking points
M1 · 1 mark · Correct factorised form for k = 5.
A1 · 1 mark · Correct roots for k = 5.
M2 · 1 mark · Correct factorised form for k = -7.
A2 · 1 mark · Correct roots for k = -7.
Worked solution
| k | Factorised form | Roots |
|---|---|---|
| 5 | (x-5)(x-1)=0 | x=5 or x=1 |
| -7 | (x-7)(x+1)=0 | x=7 or x=-1 |