Question

solve the given pair of linear equation by using elimination method:– (a) 3x+4y=10 and x-y=1. (b) 3y-5z=4 and 9y-2z=7​

Answer 1

$\huge \underline{ \blue{ \boxed{ \bf \red{Answer \:}}}}$

$\rm\pink{In(a)\ :}$

$\blue{\bold{\underline{\underline{Given :}}}}$

$x - y = 1$

$x = 1 + y$

Putting The Value Of $\small\pink{x}$ in the Equation

$\rm\pink{3 \times ( - 1) + 4y = 10}$

$\rm\pink{4y = 13}$

$\rm\pink{y = \frac{13}{4} }$

Putting The Value Of $\small\pink{y}$ in The Equation

$\rm\pink{3x + 4 \times \frac{13}{4} = 10}$

$\rm\pink{x = - 1}$

$\bf\blue{Hope\ it\ helps.}$

$\bf\pink{Plz\ Mark\ As\ Brainliest.}$

Answer 2

Given:

(a)3x+4y=10 and x-y=1​

(b)3y-5z=4 and 9y-2z=7​

To find:

Solve this by the elimination method.

Solution:

(A) In the elimination method, we just eliminate one variable to find the value of other.

• 3x+4y=10 -----(I)
• x-y=1 -----------(II)

(I) + 4(II)

3x+4y=10​

4x-4y=4

7x-0y = 14

• 7x = 14
• x = 2

Put the value of x in any of the equation.

• x-y=1
• 2-y = 1
• y = 1

The solution of 3x+4y=10 and x-y=1​ is (2,1)

(B) 3y-5z=4 and 9y-2z=7​

• 3y-5z=4--------(III)
• 9y-2z=7​ -----------(IV)

(IV) - 3(III)

 9y-2z=7​

-(9y-15z=12)

0y +13z = -5

• z = -5/13

Put the value of z in any of the equation

• 3y-5z=4
• 3y+25/13 = 4
• 3y = 4 - 25/13
• 3y = (52 - 25 )/13
• 3y = 27/13
• y = 9/13

The solution of the 3y-5z=4 and 9y-2z=7​ is (9/13, -5/13)