Question

7x-4y=20,5x+3y=26 by elimination method

Answer 1

Answer:

Step-by-step explanation: 7x-4y=20. & 5x+3y=26

Now, to equal the value of x

5(7x-4y=20) 7(5x+3y=26)

35x-20y=100 {eqn-1}

35x+21y=182. {eqn-2}

Now subtracting eqn 2 from eqn 1

35x-20y=100

35x+ 21y=182

- - -

0 - 41y=-182

Y = -182 ÷(-41)

Y = 2

Since, y=2 ..Putting in any equation

5x+3y=26

5x + 3×2= 26

5x = 26 -6

X = 20 ÷ 5

X = 4..

Therefore, x =4 & y = 2..

Answer 2

Step-by-step explanation:

${\red{\underline{\underline{\bold{Given:-}}}}}$

• 7x - 4y = 20........(1)
• 5x + 3y = 26.......(2)

${\blue{\underline{\underline{\bold{To\:Find:-}}}}}$

• The value of x and y by elimination method.

${\blue{\underline{\underline{\bold{Solution:-}}}}}$

By elimination method:-

Multiply equation (1) with 3 and equation (2) with 4

3( 7x - 4y) = 20

4( 5x + 3y) = 26

We get :-

• 21x - 12y = 60

• 20x + 12y = 104

Subtract equation (1) and (2) eliminate y

We get:-

→ 21x - 20x = 60 - 104

→ x = -44

Substitute x = -44 in equation (1)

→ 7x - 4y = 20

→ 7(-44) - 4y = 20

→ -308 - 4y = 20

→ -4y = 20 + 308

→. -4y = 328

→ y = -328/4

→ y = -82

Therefore:-

$\boxed{ x = -44}$

$\boxed{y = -82}$