Question

Please give me right answers.....​

Answer 1

Answer:

A) 80      B) 4xy    C) 24

Step-by-step explanation:

a)        $(10+2)^{2} -(10-2)^2$

          $=12^2-8^2$

          = 12 × 12 - 8 × 8

          = 144 - 64

          = 80

Therefore  $(10+2)^{2} -(10-2)^2$ = 80

b)          $(x+y)^2-(x-y)^2$

            $=x^2+y^2+2xy-(x^2+y^2-2xy)$       (Hope u know this expansion)

            = $x^2+y^2+2xy-x^2-y^2+2xy$

            = 2xy + 2xy

            = 4xy

Therefore  $(x+y)^2-(x-y)^2$ = 4xy

c)          $(10+0.6)^2-(10-0.6)^2$

             $=(10.6)^2-(9.4)^2$

             = 10.6 × 10.6 - 9.4 × 9.4

             = 112.36 - 88.36

             = 24

Therefore   $(10+0.6)^2-(10-0.6)^2$ = 24

                                           HOPE U UNDERSTOOD

                                                     THANK YOU

Answer 2

$\huge \pink{❀ꪖnswer❀}$

$using \: the \: formula \\ a {}^{2} - b {}^{2} = (a + b)(a - b)$

$(a) \: let \: (10 + 2) {}^{2} = a {}^{2} \\ (10 - 2) {}^{2} = b {}^{2} \\ therefore \\ (10 + 2) {}^{2} - (10 - 2) {}^{2} \\ = (10 + 2)(10 - 2) \\ = 12 \times 8 \\ = 96$

$(b) \: similarly \\ (x + y) {}^{2} - (x - y) {}^{2} \\ = (x + y)(x - y) \\ (multiplying) \\ = x {}^{2} - xy + xy - y {}^{2} \\ ( - xy \: and \: + xy \: gets \: cancelled) \\ = x {}^{2} - y {}^{2}$

$(c) \: (10 + 0.6) {}^{2} - (10 - 0.6) {}^{2} \\ = (10 + 0.6)(10 - 0.6) \\ = 10.6 \times 9.4 \\ = 99.64$

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