Solve each of the following systems of equations by using the method of cross multiplication:

3x + 2y + 25 = 0, 2x + y + 10 = 0.

We have,

3x + 2y + 25 = 0 …(i)


2x + y + 10 = 0 …(ii)


From equation (i), we get a1 = 3, b1 = 2 and c1 = 25


And from equation (ii), we get a2 = 2, b2 = 1 and c2 = 10


Using cross multiplication,







and


x = 5 and y = - 20


Thus, x = 5, y = - 20


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