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Solve this equation, giving your answers correct to 1 decimal place - OCR - GCSE Maths - Question 20 - 2018 - Paper 1

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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:

5(x3)+3(x+2)(x+2)(x3)=2\frac{5(x-3) + 3(x+2)}{(x+2)(x-3)} = 2

Step 2

Step 2: Expand and simplify

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Answer

Next, expand the numerator:

5(x3)+3(x+2)=5x15+3x+6=8x95(x-3) + 3(x+2) = 5x - 15 + 3x + 6 = 8x - 9

Now, we rewrite the equation as:

8x9(x+2)(x3)=2\frac{8x - 9}{(x+2)(x-3)} = 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:

8x9=2(x+2)(x3)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(x2x6)=2x22x12 2(x^2 - x - 6) = 2x^2 - 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:

2x210x+3=02x^2 - 10x + 3 = 0

Step 6

Step 6: Solve the quadratic equation

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Answer

We can use the quadratic formula:

x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

where (a = 2, b = -10, c = 3). Calculating the discriminant:

(10)24(2)(3)=10024=76(-10)^2 - 4(2)(3) = 100 - 24 = 76

Now substituting into the quadratic formula gives:

x=10±764x = \frac{10 \pm \sqrt{76}}{4}

Step 7

Step 7: Calculate the roots

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Answer

Evaluating this gives two possible solutions:

x=10+7645.3x = \frac{10 + \sqrt{76}}{4} \approx 5.3 x=107640.3x = \frac{10 - \sqrt{76}}{4} \approx -0.3

Thus, the solutions are:

Final Answers:

x = -0.3 or x = 5.3 (both rounded to one decimal place)

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