Question

QBy By elimination continue : -
2.) 3x - y -4 = 0 4x + y - 17 = 0​

Answer 1

Step-by-step explanation:

According to the rules:-

⇒Coefficient of any variable should be equal.

Example 1:2x-3y=7 (eq 1)

2x+5y=8 (eq 2)

The coefficient of x in equation 1 , (2) is same as coefficient of x in equation 2.

⇒ If having same signs then we have to subtract

example: Refer to example 1, in which both equations (2x)

is having same signs +2x-3y=7 (eq 1)

+2x+5y=8(eq 2)

⇒If having different signs, then add

Now Let's Solve:-

$3x - y = 4 \: \: (equation \: 1)$

$4x + y = 17 \: \: (equation \: 2)$

So coefficient of y in both equation is different so we'll simply add both equations.

$3x - y = 4 \\ + \: x + y = 17$

$4x = 21$

$x = 5.25$

Now put the value of x in any one of the equation:-

⇒3x-y=4

⇒3(5.25)-y=4

⇒15.75-4=y

⇒11.75=y

⇒For verification:-

⇒3x-y=4

⇒3(5.25)-(11.75)=4

⇒4=4

Hence, proved