Question 62

If 3x + 2y = 7 and 4x - y = 24, then x - y = .

Solution

Equation (i) : 3x + 2y = 7

Equation (ii) : 4x - y = 24

Multiplying by 2 on both sides, => $$8x - 2y = 48$$ -----------(iii)

Adding equation(i) and (iii),

=> $$(3x + 8x) + (2y - 2y) = (7 + 48)$$

=> $$11x = 55$$

=> $$x = \frac{55}{11} = 5$$

Substituting it in equation (ii), we get : $$4(5) - y = 24$$

=> $$y = 20 - 24 = -4$$

$$\therefore (x - y) = 5 - (-4) = 5 + 4 = 9$$

=> Ans - (A)

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