Question

x+y=7;x-y=-1.graphical.method​

Answer 1

EXPLANATION.

Graph of the equation.

⇒ x + y = 7. - - - - - (1).

⇒ x - y = -1. - - - - - (2).

As we know that,

From equation (1), we get.

⇒ x + y = 7. - - - - - (1).

Put the value of x = 0 in equation, we get.

⇒ (0) + y = 7.

⇒ y = 7.

Their Co-ordinates = (0,7).

Put the value of y = 0 in equation, we get.

⇒ x + (0) = 7.

⇒ x = 7.

Their Co-ordinates = (7,0).

From equation (2), we get.

x - y = -1. - - - - - (2).

Put the value of x = 0 in equation, we get.

⇒ (0) - y = -1.

⇒ - y = -1.

⇒ y = 1.

Their Co-ordinates = (0,1).

Put the value of y = 0 in equation, we get.

⇒ x - (0) = -1.

⇒ x = -1.

Their Co-ordinates = (-1,0).

Both curves intersect at a point = (3,4).

Answer 2

Given :-

x + y = 7……………..(1)

Let us consider x = 1

Then equation (1) becomes

1 + y = 7

y = 6

Let us consider x = 2

Then equation (1) becomes

2 + y = 7

y = 5

∴ (1,6) and (2,5) are the two solutions of x + y = 7

$\longmapsto\boxed{ \rm \: Graph: x − y = 1}$

X-intercept: value of x when y = 0

Substitute 0 for y and solve for x.

• x - 0 = 1

• x = 1

The x-intercept is ( 1,0 ) Plot this point.

Y-intercept: value of y when x = 0

Substitute 0 for x and solve for y.

• 0 − y = 1

• − y = 1

Multiply both sides by − 1. This will reverse the signs.

• − 1 ( − y ) = 1 × −1 y = −1

The y-intercept is (0,−1) Plot this point.

Draw a straight line through the points.

( -10, 10) & ( -5, 5 ) are the two solutions of x- y = 1