Question

Solve the following pair of linear equations : by elimination methode
3x - 5y = 4
2y + 7 =9x





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Answer 1

SOLUTION:

3x - 5y = 4 ---------- (i)

2y + 7 = 9x

-9x + 2y = -7

9x - 2y = 7 ------------ (ii)

Multiplying equation (i) by 3, we get,

9x - 15y = 12 -------- (iii)

Now,

Subtracting equation (ii) from (iii),

(9x - 15y) - (9x - 2y) = 12 - 7

9x - 15y - 9x + 2y = 5

-13y = 5

y = -5/13

Putting the value of y in equation (ii),

9x - 2y = 7

9x - 2(-5/13) = 7

9x + 10/13 = 7

9x = 7 - 10/13

9x = (91 - 10)/13

9x = 81/13

x = 81/13 × 1/9

x = 9/13

Hence, the value of x and y is 9/13 and -5/13 respectively.