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Algebra Difficulty 1.8 Junior Find the answer

Calculate the value of (3,1)(4,2)(3,1) \nabla (4,2) using the operation ' \nabla ' defined by (a,b)(c,d)=ac+bd(a, b) \nabla (c, d)=ac+bd.

A number or a short expression. Spacing and $ signs are ignored.

Solution

From the definition, (3,1)(4,2)=(3)(4)+(1)(2)=12+2=14(3,1) \nabla (4,2)=(3)(4)+(1)(2)=12+2=14.

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