If x[(2)(3)]+y[(-1)(1)]=[(10)(5)] then the value of xy is: 1. 3 2. -12 3. -6 4. 15

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KnowledgeBoat · Accepted Answer

Solving for x and y: ∴ 2x - y = 10 ....(1) ∴ 3x + y = 5 .....(2) Adding equations (1) and (2), we get : ⇒ 2x - y + 3x + y = 10 + 5 ⇒ 2x + 3x = 15 ⇒ 5x = 15 ⇒ x = ⇒ x = 3. Substituting value of x in 2x - y = 10, we get : ⇒ 2(3) - y = 10 ⇒ 6 - y = 10 ⇒ y = 6 - 10 ⇒ y = -4. ∴ xy = (3)(-4) = -12. Hence, option 2 is the correct option.

Mathematics

If x[(2)(3)]+y[(-1)(1)]=[(10)(5)] then the value of xy is: 1. 3 2. -12 3. -6 4. 15

Matrices

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