Question

3x-4y+2z=-1 , 2x+3y+5z=-1 , x+z=2,then x=

Answer 1

Hey friend, Harish here.

Here is your answer:

Given that,

3x - 4y + 2x = -1    - (i)

2x + 3y + 5x = -1  - (ii)

x + z = 2  - (iii)

To find,

The value of x.

Solution,

Given that,

x + z = 2.

So,  z = 2-x. 

Now, substitute the value of z in equation (i).

Then,

⇒ $3x - 4y + 2(2-x) = -1$

⇒ $3x - 2x - 4y + 4 = -1$

⇒ $x - 4y = -5$

⇒ $4y = x + 5$

⇒ $y = \frac{x+5}{4}$

Now, substitute value of both z & y in equation (ii).

Then, 

⇒ $2 x +3( \frac{x+5}{4})+ 5(2-x) = -1$

⇒ $2x + \frac{3x+15}{4} +10-5x=-1$

⇒ $2x-5x+ \frac{3x+15}{4} =-11$

⇒ $\frac{3x+15}{4}-3x=-11$

⇒ $\frac{3x+15-12x}{4} =-11$

⇒ $15-9x = -44$

⇒ $9x = 15 + 44 = 59$

⇒ $x = \frac{59}{9}$
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Hope my answer is helpful to you.