A student thinks of a number - OCR - GCSE Maths - Question 9 - 2021 - Paper 1
Question 9
A student thinks of a number.
They square it and then add 6.
Their answer is 295.
What number is the student thinking of?
Worked Solution & Example Answer:A student thinks of a number - OCR - GCSE Maths - Question 9 - 2021 - Paper 1
Step 1
Set up the equation based on the problem statement
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Answer
Let the number the student is thinking of be represented by the variable x. According to the problem, when this number is squared and then increased by 6, the result is 295. This can be formulated as:
x2+6=295
Step 2
Solve the equation for x
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Answer
To isolate x2, subtract 6 from both sides:
x2=295−6
This simplifies to:
x2=289
Step 3
Find the square root of both sides
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Answer
To find the value of x, take the square root of both sides:
x = rac{± ext{sqrt}(289)}{1}
Thus, we find:
x=17extorx=−17
Step 4
Identify the number the student was thinking of
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Answer
Since the problem context suggests a positive number, the final answer is:
x=17
Therefore, the number the student is thinking of is 17.