Solve (3+sqrt(5))(3-sqrt(5))= | Equatix - Math Solver

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Example

3(r+2s)=2t-4

a⋅(b-2)=3b

3(r+2s)=2t-4

a⋅(b-2)=3b

Question

$$(3+ \sqrt{ 5 } )(3- \sqrt{ 5 } )=$$

Evaluate

$4$

Solution Steps

Multiplication can be transformed into difference of squares using the rule: $\left(a-b\right)\left(a+b\right)=a^{2}-b^{2}$.

$$3^{2}-\left(\sqrt{5}\right)^{2}$$

Calculate $3$ to the power of $2$ and get $9$.

$$9-\left(\sqrt{5}\right)^{2}$$

The square of $\sqrt{5}$ is $5$.

$$9-5$$

Subtract $5$ from $9$ to get $4$.

$$4$$

Factor

$2^{2}$