Q2 of 86 Page 56

Evaluate the following products without actual multiplication.

30.5 × 29.5

30.5 = and 29.5 =


30.5 × 29.5 = ×


30.5 × 29.5 = ×


30.5 × 29.5 = …(i)


Consider 61 × 59


61 = (60 + 1)


59 = (60 – 1)


61 × 59 = (60 + 1)(60 – 1)


using the identity (a + b) × (a – b) = a2 – b2


here a = 60 and b = 1


61 × 59 = 602 – 12


61 × 59 = 3600 – 1


61 × 59 = 3599


From (i)


30.5 × 29.5 =


Therefore 30.5 × 29.5 = 899.75


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