Given that
$x^2 \cdot (3x + 5) = 1 : 2$
find the possible values of x. - Edexcel - GCSE Maths - Question 19 - 2019 - Paper 1
Question 19
Given that
$x^2 \cdot (3x + 5) = 1 : 2$
find the possible values of x.
Worked Solution & Example Answer:Given that
$x^2 \cdot (3x + 5) = 1 : 2$
find the possible values of x. - Edexcel - GCSE Maths - Question 19 - 2019 - Paper 1
Step 1
Step 1: Form the Equation
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Answer
To solve for the possible values of x, we first rewrite the equation from the given ratio:
x2⋅(3x+5)=1/2
Multiplying both sides by 2 gives:
2x2(3x+5)=1
Step 2
Step 2: Simplify the Equation
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Answer
Expanding the left side, we have:
6x3+10x2=1
Rearranging the equation results in:
6x3+10x2−1=0
Step 3
Step 3: Solve the Cubic Equation
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Answer
Next, we can use numerical methods or factoring if we recognize any possible roots. Trying values using the Rational Root Theorem may lead us to:
x=−31,x=21
After testing these values in the equation, we can confirm them as roots.
Step 4
Step 4: Conclude Possible Values
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Answer
The possible values of x satisfying the equation are: