Solve this equation, giving your answers correct to 1 decimal place - OCR - GCSE Maths - Question 20 - 2018 - Paper 1
Question 20
Solve this equation, giving your answers correct to 1 decimal place.
$$\frac{5}{x+2} + \frac{3}{x-3} = 2$$
Worked Solution & Example Answer:Solve this equation, giving your answers correct to 1 decimal place - OCR - GCSE Maths - Question 20 - 2018 - Paper 1
Step 1
Step 1: Rearrange the equation
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Answer
Start by rewriting the equation with a common denominator. The common denominator for the left side is ((x+2)(x-3)). Thus, we can express the equation as:
(x+2)(x−3)5(x−3)+3(x+2)=2
Step 2
Step 2: Expand and simplify
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Answer
Next, expand the numerator:
5(x−3)+3(x+2)=5x−15+3x+6=8x−9
Now, we rewrite the equation as:
(x+2)(x−3)8x−9=2
Step 3
Step 3: Eliminate the fraction
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Answer
Multiply both sides by ((x+2)(x-3)) to eliminate the fraction:
8x−9=2(x+2)(x−3)
Step 4
Step 4: Expand the right side
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Answer
Expanding the right side gives:
2(x2−x−6)=2x2−2x−12
Step 5
Step 5: Rearrange into a quadratic equation
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Answer
Now, we can rearrange the equation into standard form:
2x2−10x+3=0
Step 6
Step 6: Solve the quadratic equation
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Answer
We can use the quadratic formula:
x=2a−b±b2−4ac
where (a = 2, b = -10, c = 3).
Calculating the discriminant:
(−10)2−4(2)(3)=100−24=76
Now substituting into the quadratic formula gives:
x=410±76
Step 7
Step 7: Calculate the roots
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Answer
Evaluating this gives two possible solutions:
x=410+76≈5.3x=410−76≈−0.3
Thus, the solutions are:
Final Answers:
x = -0.3 or x = 5.3 (both rounded to one decimal place)