Question

If A = 4x + 7y - 6z
B = 3x + 4y + 2z
C= 6x + 8y - 5z
Find A+ [B-C]

Answer 1

Answer:

x+2y+4z = a _____ (1)

3x-y+5z = b _____ (2)

2x-3y+z = c _____ (3)

multiplying eq (1) by (3) and then subtract from (2)

3x+6y+12z = 3a

3x - y + 5z = b

(-) (+) (-) = (-)

_____________

7y + 7z = 3a - b __ __ _ __ _(4)

multiplying eq (3) by (3) & (2) by (2) then subtract

6x - 2y + 10z = 2b

6x - 9y + 3z = 3c

(-) (+) (-) (-)

_____________

7y + 7z = 2b - 3c ___________ (5)

now, if given equation have more then two solution

then

7

7

=

7

7

=

2b−3c

3a−b

3a-b = 2b - 3c

3a + 3c = 3b

a + c = b

[b - a = c]

Answer 2

Answer:

Correct option is A)

x+2y+4z = a _____ (1)

3x-y+5z = b _____ (2)

2x-3y+z = c _____ (3)

multiplying eq (1) by (3) and then subtract from (2)

3x+6y+12z = 3a

3x - y + 5z = b

(-) (+) (-) = (-)

_____________

7y + 7z = 3a - b __ __ _ __ _(4)

multiplying eq (3) by (3) & (2) by (2) then subtract

6x - 2y + 10z = 2b

6x - 9y + 3z = 3c

(-) (+) (-) (-)

_____________

7y + 7z = 2b - 3c ___________ (5)

now, if given equation have more then two solution

then

7

7

=

7

7

=

2b−3c

3a−b

3a-b = 2b - 3c

3a + 3c = 3b

a + c = b

[b - a = c]