Solve 2/13x-2-5/3x-7

$$\frac{ 2 }{ 13x-2 } - \frac{ 5 }{ 3x-7 }$$

Evaluate

$$-\frac{59x+4}{\left(3x-7\right)\left(13x-2\right)}$$

Short Solution Steps

To add or subtract expressions, expand them to make their denominators the same. Least common multiple of 13x-2 and 3x-7 is \left(3x-7\right)\left(13x-2\right). Multiply \frac{2}{13x-2} times \frac{3x-7}{3x-7}. Multiply \frac{5}{3x-7} times \frac{13x-2}{13x-2}.

$$\frac{2\left(3x-7\right)}{\left(3x-7\right)\left(13x-2\right)}-\frac{5\left(13x-2\right)}{\left(3x-7\right)\left(13x-2\right)}$$

Since \frac{2\left(3x-7\right)}{\left(3x-7\right)\left(13x-2\right)} and \frac{5\left(13x-2\right)}{\left(3x-7\right)\left(13x-2\right)} have the same denominator, subtract them by subtracting their numerators.

$$\frac{2\left(3x-7\right)-5\left(13x-2\right)}{\left(3x-7\right)\left(13x-2\right)}$$

Do the multiplications in 2\left(3x-7\right)-5\left(13x-2\right).

$$\frac{6x-14-65x+10}{\left(3x-7\right)\left(13x-2\right)}$$

Combine like terms in 6x-14-65x+10.

$$\frac{-59x-4}{\left(3x-7\right)\left(13x-2\right)}$$

Expand \left(3x-7\right)\left(13x-2\right).

$$\frac{-59x-4}{39x^{2}-97x+14}$$

Differentiate w.r.t. x

$$\frac{2301x^{2}+312x-1214}{1521x^{4}-7566x^{3}+10501x^{2}-2716x+196}$$

Steps Using Derivative Rule for Quotient

To add or subtract expressions, expand them to make their denominators the same. Least common multiple of 13x-2 and 3x-7 is \left(3x-7\right)\left(13x-2\right). Multiply \frac{2}{13x-2} times \frac{3x-7}{3x-7}. Multiply \frac{5}{3x-7} times \frac{13x-2}{13x-2}.

$$\frac{\mathrm{d}}{\mathrm{d}x}(\frac{2\left(3x-7\right)}{\left(3x-7\right)\left(13x-2\right)}-\frac{5\left(13x-2\right)}{\left(3x-7\right)\left(13x-2\right)})$$

Since \frac{2\left(3x-7\right)}{\left(3x-7\right)\left(13x-2\right)} and \frac{5\left(13x-2\right)}{\left(3x-7\right)\left(13x-2\right)} have the same denominator, subtract them by subtracting their numerators.

$$\frac{\mathrm{d}}{\mathrm{d}x}(\frac{2\left(3x-7\right)-5\left(13x-2\right)}{\left(3x-7\right)\left(13x-2\right)})$$

Do the multiplications in 2\left(3x-7\right)-5\left(13x-2\right).

$$\frac{\mathrm{d}}{\mathrm{d}x}(\frac{6x-14-65x+10}{\left(3x-7\right)\left(13x-2\right)})$$

Combine like terms in 6x-14-65x+10.

$$\frac{\mathrm{d}}{\mathrm{d}x}(\frac{-59x-4}{\left(3x-7\right)\left(13x-2\right)})$$

Apply the distributive property by multiplying each term of 3x-7 by each term of 13x-2.

$$\frac{\mathrm{d}}{\mathrm{d}x}(\frac{-59x-4}{39x^{2}-6x-91x+14})$$

Combine -6x and -91x to get -97x.

$$\frac{\mathrm{d}}{\mathrm{d}x}(\frac{-59x-4}{39x^{2}-97x+14})$$

For any two differentiable functions, the derivative of the quotient of two functions is the denominator times the derivative of the numerator minus the numerator times the derivative of the denominator, all divided by the denominator squared.

$$\frac{\left(39x^{2}-97x^{1}+14\right)\frac{\mathrm{d}}{\mathrm{d}x}(-59x^{1}-4)-\left(-59x^{1}-4\right)\frac{\mathrm{d}}{\mathrm{d}x}(39x^{2}-97x^{1}+14)}{\left(39x^{2}-97x^{1}+14\right)^{2}}$$

The derivative of a polynomial is the sum of the derivatives of its terms. The derivative of a constant term is 0. The derivative of ax^{n} is nax^{n-1}.

$$\frac{\left(39x^{2}-97x^{1}+14\right)\left(-59\right)x^{1-1}-\left(-59x^{1}-4\right)\left(2\times 39x^{2-1}-97x^{1-1}\right)}{\left(39x^{2}-97x^{1}+14\right)^{2}}$$

Simplify.

$$\frac{\left(39x^{2}-97x^{1}+14\right)\left(-59\right)x^{0}-\left(-59x^{1}-4\right)\left(78x^{1}-97x^{0}\right)}{\left(39x^{2}-97x^{1}+14\right)^{2}}$$

Multiply 39x^{2}-97x^{1}+14 times -59x^{0}.

$$\frac{39x^{2}\left(-59\right)x^{0}-97x^{1}\left(-59\right)x^{0}+14\left(-59\right)x^{0}-\left(-59x^{1}-4\right)\left(78x^{1}-97x^{0}\right)}{\left(39x^{2}-97x^{1}+14\right)^{2}}$$

Multiply -59x^{1}-4 times 78x^{1}-97x^{0}.

$$\frac{39x^{2}\left(-59\right)x^{0}-97x^{1}\left(-59\right)x^{0}+14\left(-59\right)x^{0}-\left(-59x^{1}\times 78x^{1}-59x^{1}\left(-97\right)x^{0}-4\times 78x^{1}-4\left(-97\right)x^{0}\right)}{\left(39x^{2}-97x^{1}+14\right)^{2}}$$

To multiply powers of the same base, add their exponents.

$$\frac{39\left(-59\right)x^{2}-97\left(-59\right)x^{1}+14\left(-59\right)x^{0}-\left(-59\times 78x^{1+1}-59\left(-97\right)x^{1}-4\times 78x^{1}-4\left(-97\right)x^{0}\right)}{\left(39x^{2}-97x^{1}+14\right)^{2}}$$

Simplify.

$$\frac{-2301x^{2}+5723x^{1}-826x^{0}-\left(-4602x^{2}+5723x^{1}-312x^{1}+388x^{0}\right)}{\left(39x^{2}-97x^{1}+14\right)^{2}}$$

Combine like terms.

$$\frac{2301x^{2}+312x^{1}-1214x^{0}}{\left(39x^{2}-97x^{1}+14\right)^{2}}$$

For any term t, t^{1}=t.

$$\frac{2301x^{2}+312x-1214x^{0}}{\left(39x^{2}-97x+14\right)^{2}}$$

For any term t except 0, t^{0}=1.

$$\frac{2301x^{2}+312x-1214}{\left(39x^{2}-97x+14\right)^{2}}$$