Question

PLEASE NO SPAM -100 POINTS FOR THE BEST ANSWER! Expand the following using a suitable identity a) (x + 13)(x + 20) b) (x – 7)(x – 7) c) (3a – 1.5)(3a+1.5) Please do all questions

Answer 1

$\huge{\red{\rm{ \underline{Answer}}}}$

(A) We know,

$(x + a)(x + b) = {x}^{2} + (b + a)x + ab$

$∴(x + 13)(x + 20) \\ ⇒ {x}^{2} + (20 + 13)x + 13 \times 20 \\ ⇒ {x}^{2} + 33x + 260$

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(B) We know,

$(a - b)(a - b) = {a}^{2} - 2ab + {b}^{2} = {(a - b)}^{2}$

$∴(x - 7)(x - 7) \\ ⇒ {(x - 7)}^{2} \\ ⇒ {(x)}^{2} - 2.x.7 + {(7)}^{2} \\ ⇒ {x}^{2} - 14x + 49$

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(C) We know,

$(a - b)(a + b) = {a}^{2} - {b}^{2}$

$∴(3a - 1.5)(3a+1.5) \\ ⇒ {(3a)}^{2} - {(1.5)}^{2} \\ ⇒9 {a}^{2} - 2.25$

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Answer 2

Answer:

We have,

We have,(x+13)(x+20)

We have,(x+13)(x+20)=x

We have,(x+13)(x+20)=x 2

We have,(x+13)(x+20)=x 2 +20x+13x+260

We have,(x+13)(x+20)=x 2 +20x+13x+260=x

We have,(x+13)(x+20)=x 2 +20x+13x+260=x 2

We have,(x+13)(x+20)=x 2 +20x+13x+260=x 2 +33x+260

We have,(x+13)(x+20)=x 2 +20x+13x+260=x 2 +33x+260Hence, this is the answer.