Question

$simplify \: (6x + 3y)^{2} + (6x - 3y) ^{2}$
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Answer 1

Answer:

• Answer of simplify is 72$\sf{x}^{2}$+18$\sf{y}^{2}$

Step-by-step explanation:

We know that,

$\: \: \sf \rightarrow \: {(a + b)}^{2} = {(a)}^{2} + {(b)}^{2} + 2ab \\ \\ \: \: \sf \rightarrow \: {(a - b)}^{2} = {(a)}^{2} + {(b)}^{2} - 2ab$

Here we have to use this formula for simplifying

$\: \: \sf \: {(6x + 3y)}^{2} + {(6x - 3y)}^{2} \\ \\ \: \: \sf \implies \: {(6x)}^{2} + {(3y)}^{2} + 2.6x.3y + {(6x)}^{2} + {(3y)}^{2} - 2.6x.3y$

Now find square of numbers and multiply the numbers

$\: \: \sf \implies \: 36 {x}^{2} + 9 {y}^{2} + 36xy + 36 {x}^{2} + 9 {y}^{2} - 36xy$

Rearrange the numbers

$\: \: \sf \implies \: 36 {x}^{2} + 36 {x}^{2} + 9 {y}^{2} + 9 {y}^{2} + 36xy - 36xy$

Add the numbers

$\: \: \sf \implies \: 72 {x}^{2} + 18 {y}^{2} + 36xy - 36xy$

Now subtract 36xy and (-36xy)

$\: \: \sf \implies \: 72{x}^{2} + 18 {y}^{2} + 0$

Hence,72$\sf{x}^{2}$+18$\sf{y}^{2}$