Question

By solving a pair of Linear equations x + y=20 and x-y=10, the values of audy are. A) 15 &5 B) 5& 15 C) 18 & 2 D) 2&18​

Answer 1

Answer:

A) 15 &5

Step-by-step explanation:

we have

x+y=20 ------eq.1

x-y=10--------eq.2

from eq.2

x=10+y--------eq.3

put eq.3 in eq.1

10+y+y= 20

10+2y=20

2y= 20-10

2y=10

y=5

put y=5 in eq.2

so x-5=10

x=10+5

x= 15

hence value of x is 15 and value of y is 5

Answer 2

Concept

Linear equation is an equation between two variables that gives a straight line when plotted.

Given

A pair of Linear equations x + y=20 and x-y=10 is given

Find

We need to find the value of x and y

Solution

x+y= 20.........(1)

From equation (1) we get, x = 20-y

x-y = 10...........(2)

Put the value of x in equation (2), we get

20-y-y = 10

20-10 = 2y

2y = 10

y = 10/2

y = 5

Put this value of y in equation (1)

x + 5 = 20

x= 20-5

x= 15

Hence the value of x is 15 and the value of y is 5

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