Question

Q1.Solve
x+y=15 ; 2x-y=3

Answer 1

Explanation:

Given

We have given two Equations : x+y= 15 & 2x-y=3

To find

We have to find x and y

$]\sf\huge\bold{\underline{\underline{{Solution}}}} </p><p>Solution$

We can solve the above given two linear equations through various ways .Here ,we solve through substitution method.

Simplest method

➙x+y= 15------(1)

➙2x-y=3-------(2)

Adding Equation 1 and 2

➙x+y+2x-y= 15+3

➙3x-y+y= 18

➙3x=18

➙x= 18÷3

➙x= 6

Put x 's value into equation 1

➙x+y= 15

➙6+y=15

➙y=15-6

y= 9

Check:

➙x+y= 15

➙6+9=15

Since,LHS = RHS(Verified)

Alternative Method:

➙x+y= 15------(1)

➙2x-y= 3-------(2)

From equation 1

x= 15-y-----(3)

Put Equation 3 into 2

➙2(15-y)-y= 3

➙30-2y-y=3

➙30-3y=3

➙-3y= 3-30

➙-3y= -27

➙y= -27÷-3

y= 9

Put y's value into equation 3

➙x= 15-y

➙x= 15-9

➙x= 6

x=6

Answer 2

Answer:

// Solve equation [2] for the variable x

[2] x = y + 3

// Plug this in for variable x in equation [1]

[1] 2•(y +3) + y = 15

[1] 3y = 9

// Solve equation [1] for the variable y

[1] 3y = 9

[1] y = 3

// By now we know this much :

x = y+3

y = 3

// Use the y value to solve for x

x = (3)+3 = 6

Solution :

{x,y} = {6,3}

Explanation:

Hope it will help you.