Solve 7y/y^2+4y+3/frac{1{y+3}+4/y+1}

$$\frac{ \frac{ 7y }{ { y }^{ 2 } +4y+3 } }{ \frac{ 1 }{ y+3 } + \frac{ 4 }{ y+1 } }$$

Evaluate

$$\frac{7y}{5y+13}$$

Short Solution Steps

To add or subtract expressions, expand them to make their denominators the same. Least common multiple of y+3 and y+1 is \left(y+1\right)\left(y+3\right). Multiply \frac{1}{y+3} times \frac{y+1}{y+1}. Multiply \frac{4}{y+1} times \frac{y+3}{y+3}.

$$\frac{\frac{7y}{y^{2}+4y+3}}{\frac{y+1}{\left(y+1\right)\left(y+3\right)}+\frac{4\left(y+3\right)}{\left(y+1\right)\left(y+3\right)}}$$

Since \frac{y+1}{\left(y+1\right)\left(y+3\right)} and \frac{4\left(y+3\right)}{\left(y+1\right)\left(y+3\right)} have the same denominator, add them by adding their numerators.

$$\frac{\frac{7y}{y^{2}+4y+3}}{\frac{y+1+4\left(y+3\right)}{\left(y+1\right)\left(y+3\right)}}$$

Do the multiplications in y+1+4\left(y+3\right).

$$\frac{\frac{7y}{y^{2}+4y+3}}{\frac{y+1+4y+12}{\left(y+1\right)\left(y+3\right)}}$$

Combine like terms in y+1+4y+12.

$$\frac{\frac{7y}{y^{2}+4y+3}}{\frac{5y+13}{\left(y+1\right)\left(y+3\right)}}$$

Divide \frac{7y}{y^{2}+4y+3} by \frac{5y+13}{\left(y+1\right)\left(y+3\right)} by multiplying \frac{7y}{y^{2}+4y+3} by the reciprocal of \frac{5y+13}{\left(y+1\right)\left(y+3\right)}.

$$\frac{7y\left(y+1\right)\left(y+3\right)}{\left(y^{2}+4y+3\right)\left(5y+13\right)}$$

Factor the expressions that are not already factored.

$$\frac{7y\left(y+1\right)\left(y+3\right)}{\left(y+1\right)\left(y+3\right)\left(5y+13\right)}$$

Cancel out \left(y+1\right)\left(y+3\right) in both numerator and denominator.

$$\frac{7y}{5y+13}$$

Differentiate w.r.t. y

$$\frac{91}{\left(5y+13\right)^{2}}$$

Steps Using Derivative Rule for Quotient

To add or subtract expressions, expand them to make their denominators the same. Least common multiple of y+3 and y+1 is \left(y+1\right)\left(y+3\right). Multiply \frac{1}{y+3} times \frac{y+1}{y+1}. Multiply \frac{4}{y+1} times \frac{y+3}{y+3}.

$$\frac{\mathrm{d}}{\mathrm{d}y}(\frac{\frac{7y}{y^{2}+4y+3}}{\frac{y+1}{\left(y+1\right)\left(y+3\right)}+\frac{4\left(y+3\right)}{\left(y+1\right)\left(y+3\right)}})$$

Since \frac{y+1}{\left(y+1\right)\left(y+3\right)} and \frac{4\left(y+3\right)}{\left(y+1\right)\left(y+3\right)} have the same denominator, add them by adding their numerators.

$$\frac{\mathrm{d}}{\mathrm{d}y}(\frac{\frac{7y}{y^{2}+4y+3}}{\frac{y+1+4\left(y+3\right)}{\left(y+1\right)\left(y+3\right)}})$$

Do the multiplications in y+1+4\left(y+3\right).

$$\frac{\mathrm{d}}{\mathrm{d}y}(\frac{\frac{7y}{y^{2}+4y+3}}{\frac{y+1+4y+12}{\left(y+1\right)\left(y+3\right)}})$$

Combine like terms in y+1+4y+12.

$$\frac{\mathrm{d}}{\mathrm{d}y}(\frac{\frac{7y}{y^{2}+4y+3}}{\frac{5y+13}{\left(y+1\right)\left(y+3\right)}})$$

Divide \frac{7y}{y^{2}+4y+3} by \frac{5y+13}{\left(y+1\right)\left(y+3\right)} by multiplying \frac{7y}{y^{2}+4y+3} by the reciprocal of \frac{5y+13}{\left(y+1\right)\left(y+3\right)}.

$$\frac{\mathrm{d}}{\mathrm{d}y}(\frac{7y\left(y+1\right)\left(y+3\right)}{\left(y^{2}+4y+3\right)\left(5y+13\right)})$$

Factor the expressions that are not already factored in \frac{7y\left(y+1\right)\left(y+3\right)}{\left(y^{2}+4y+3\right)\left(5y+13\right)}.

$$\frac{\mathrm{d}}{\mathrm{d}y}(\frac{7y\left(y+1\right)\left(y+3\right)}{\left(y+1\right)\left(y+3\right)\left(5y+13\right)})$$

Cancel out \left(y+1\right)\left(y+3\right) in both numerator and denominator.

$$\frac{\mathrm{d}}{\mathrm{d}y}(\frac{7y}{5y+13})$$

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.

$$\frac{\left(5y^{1}+13\right)\frac{\mathrm{d}}{\mathrm{d}y}(7y^{1})-7y^{1}\frac{\mathrm{d}}{\mathrm{d}y}(5y^{1}+13)}{\left(5y^{1}+13\right)^{2}}$$

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}.

$$\frac{\left(5y^{1}+13\right)\times 7y^{1-1}-7y^{1}\times 5y^{1-1}}{\left(5y^{1}+13\right)^{2}}$$

Do the arithmetic.

$$\frac{\left(5y^{1}+13\right)\times 7y^{0}-7y^{1}\times 5y^{0}}{\left(5y^{1}+13\right)^{2}}$$

Expand using distributive property.

$$\frac{5y^{1}\times 7y^{0}+13\times 7y^{0}-7y^{1}\times 5y^{0}}{\left(5y^{1}+13\right)^{2}}$$

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

$$\frac{5\times 7y^{1}+13\times 7y^{0}-7\times 5y^{1}}{\left(5y^{1}+13\right)^{2}}$$

Do the arithmetic.

$$\frac{35y^{1}+91y^{0}-35y^{1}}{\left(5y^{1}+13\right)^{2}}$$

Combine like terms.

$$\frac{\left(35-35\right)y^{1}+91y^{0}}{\left(5y^{1}+13\right)^{2}}$$

Subtract 35 from 35.

$$\frac{91y^{0}}{\left(5y^{1}+13\right)^{2}}$$

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

$$\frac{91y^{0}}{\left(5y+13\right)^{2}}$$

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

$$\frac{91\times 1}{\left(5y+13\right)^{2}}$$

For any term t, t\times 1=t and 1t=t.

$$\frac{91}{\left(5y+13\right)^{2}}$$