Page 13 - 10th maths -1

Dividing both sides of the equation by 32.

x + y = 1 . . . (III)

Now, let’s subtract equation (II) from (I)

15x + 17y = 21
-
17x + 15y = 11
- - -
-2x + 2y = 10

dividing the equation by 2.

-x + y = 5 . . . (IV)

Now let’s add equations (III) and (V).

x + y = 1
+
-x + y = 5
\ 2y = 6 \ y = 3

Place this value in equation (III).

x + y = 1

\ x + 3 = 1

\ x = 1 - 3 \ x = -2

(x, y) = (-2, 3) is the solution.

Practice Set 1.1

(1) Complete the following activity to solve the simultaneous equations.

5x + 3y = 9 -----(I)

2x + 3y = 12 ----- (II) Place x = 3 in equation (I).

Let’s add eqations (I) and (II). 5 ´ + 3y = 9
5x + 3y = 9 3y = 9 -
+ 3y =
2x - 3y = 12
x = y =
3
x = x = y =

\ Solution is (x, y) = ( , ).

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