Find the products using suitable identity: a) (t –2)(t –2) b) (3y –2z) (3y + 2z) c) 105 × 98

Question

Find the products using suitable identity:
a) (t –2)(t –2)
b) (3y –2z) (3y + 2z)
c) 105 × 98

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Eirian 1 day 2021-07-21T05:20:18+00:00 2 Answers 0 views 0

Answers ( )

    0
    2021-07-21T05:21:31+00:00

    Answer:

    Step-by-step explanation:

    a) Identity : (a- b)² = a²- 2ab +  b²

    (t – 2)(t -2) = (t-2)²            {a = t & b =2}

                     = t² -2*t*2 + 2²

                     = t² – 4t + 4

    b) (a + b)(a – b) = a² – b²

    a = 3y   & y = 2z

    (3y – 2z) (3y +2z)  = (3y)² – (2z)²

                                 = 3²y² – 2²z²

                                  = 9y² – 4z²

    c) (x + a)(x + b) =x² + (a+b)x + ab

    105 * 98 = (100 + 5) (100 – 2)  {here, x = 100 ; a = 5 ; b = -2}

                  = 100² + (5 +(-2) ) *100 + (5)*(-2)

                  = 10000 + (3)*100 – 10

                  = 10000 + 300 – 10

                  = 10290

    0
    2021-07-21T05:22:13+00:00

    Hello!

    a) (t – 2)(t – 2) = (t – 2)² = t² 4t + 4

    b) (3y – 2z)(3y + 2z) = (3y)² – (2z)² = 9y² 4z²

    c) 105 × 98 = 10290

    Good luck! 🙂

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )