Question

4 Here are two simultaneous equations.
3x + 2y=38
x - 2y = 2
Will you add or subtract
to eliminate y?
a Find the value of 4x
b Find the values of x and y.​

Answer 1

Answer:

add

so result would be 4x=40

x=10

10-2y=2

8=2y

y=4

Answer 2

$\huge\mathfrak{Answer}$

We must obviously add y as in the sign of y differs in both the equations so we should add them to eliminate y completely like this →

3x + 2y = 38 ____ ( i )

x - 2y = 2 _______ ( ii )

Adding both the equations we get ,

3x + 2y = 38

+ x - 2y = 2

---------------------

4x = 40

Solving 4x = 40 we get ,

4x = 40

→ x = 10

After substituting the value of x in equation 2 we get ,

x - 2y = 2

=> 10 - 2y = 2

=> 2y = 10 - 2

=> y = 8/2

=> y = 4

Therefore, the value of x and y is 10 and 4

▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃

Notes :-

• If we would have substracted then y would not have got eliminated -

3x + 2y = 38

- x - 2y = 2

( - ) ( + ) ( - )

---------------------

2x + 4y = 36

Thus, y would have remained in the equation .