Solve frac{5p^{3}q^2}{45p^4q-35p^2q^3}=

$$\frac { 5 p ^ { 3 } q ^ { 2 } } { 45 p ^ { 4 } q - 35 p ^ { 2 } q ^ { 3 } } =$$

Evaluate

$$\frac{pq}{9p^{2}-7q^{2}}$$

Short Solution Steps

Factor the expressions that are not already factored.

$$\frac{5q^{2}p^{3}}{5qp^{2}\left(9p^{2}-7q^{2}\right)}$$

Cancel out 5qp^{2} in both numerator and denominator.

$$\frac{pq}{9p^{2}-7q^{2}}$$

Differentiate w.r.t. p

$$\frac{q\left(-9p^{2}-7q^{2}\right)}{\left(9p^{2}-7q^{2}\right)^{2}}$$

Steps Using Derivative Rule for Quotient

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.

$$\frac{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)\frac{\mathrm{d}}{\mathrm{d}p}(5q^{2}p^{3})-5q^{2}p^{3}\frac{\mathrm{d}}{\mathrm{d}p}(45qp^{4}+\left(-35q^{3}\right)p^{2})}{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)^{2}}$$

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}.

$$\frac{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)\times 3\times 5q^{2}p^{3-1}-5q^{2}p^{3}\left(4\times 45qp^{4-1}+2\left(-35q^{3}\right)p^{2-1}\right)}{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)^{2}}$$

Simplify.

$$\frac{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)\times 15q^{2}p^{2}-5q^{2}p^{3}\left(180qp^{3}+\left(-70q^{3}\right)p^{1}\right)}{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)^{2}}$$

Multiply 45qp^{4}+\left(-35q^{3}\right)p^{2} times 15q^{2}p^{2}.

$$\frac{45qp^{4}\times 15q^{2}p^{2}+\left(-35q^{3}\right)p^{2}\times 15q^{2}p^{2}-5q^{2}p^{3}\left(180qp^{3}+\left(-70q^{3}\right)p^{1}\right)}{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)^{2}}$$

Multiply 5q^{2}p^{3} times 180qp^{3}+\left(-70q^{3}\right)p^{1}.

$$\frac{45qp^{4}\times 15q^{2}p^{2}+\left(-35q^{3}\right)p^{2}\times 15q^{2}p^{2}-\left(5q^{2}p^{3}\times 180qp^{3}+5q^{2}p^{3}\left(-70q^{3}\right)p^{1}\right)}{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)^{2}}$$

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

$$\frac{45q\times 15q^{2}p^{4+2}+\left(-35q^{3}\right)\times 15q^{2}p^{2+2}-\left(5q^{2}\times 180qp^{3+3}+5q^{2}\left(-70q^{3}\right)p^{3+1}\right)}{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)^{2}}$$

Simplify.

$$\frac{675q^{3}p^{6}+\left(-525q^{5}\right)p^{4}-\left(900q^{3}p^{6}+\left(-350q^{5}\right)p^{4}\right)}{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)^{2}}$$

Combine like terms.

$$\frac{\left(-225q^{3}\right)p^{6}+\left(-175q^{5}\right)p^{4}}{\left(45qp^{4}+\left(-35q^{3}\right)p^{2}\right)^{2}}$$