Solve (7 + sqrt(5))(7 - 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

$$(7+\sqrt{5})(7-\sqrt{5})$$

Evaluate

$44$

Solution Steps

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

$$7^{2}-\left(\sqrt{5}\right)^{2}$$

Calculate $7$ to the power of $2$ and get $49$.

$$49-\left(\sqrt{5}\right)^{2}$$

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

$$49-5$$

Subtract $5$ from $49$ to get $44$.

$$44$$

Factor

$2^{2}\times 11$