Question 91

If a - b = -6 and $$a^2 + b^2$$ = 44, then ab is

Solution

Given : $$(a - b) = -6$$ and $$a^2 + b^2 = 44$$

Using $$(a - b)^2 = a^2 + b^2 - 2ab$$

=> $$(-6)^2 = 44 - (2 \times ab)$$

=> $$2 ab = 44 - 36 = 8$$

=> $$ab = \frac{8}{2} = 4$$

=> Ans - (C)

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