Question

. Find the point of intersection of the lines x + y = 7 and y = – 3 both algebraically and
graphically.

Answer 1

Answer:

Correct option is

C

(6,1)

For line 2x−3y=9

x 0 6

y −3 1

For line x+y=7

x 5 2

y 6 1

x+y=7 ----- (1)

2x−3y=9 ----- (2)

From equation (1)

y=7−x ------ (3)

Assume the value of x=5,6 and put those values in equation (3)

If x=5,y=7−5=2

If x=6,y=7−6=1

Now plotting (5, 2), (6, 1) and joining them, we get a straight line.

From equation (2),

2x−3y=9

y=

3

2x−9

------ (4)

Assume the value of x=0,6 and put those values in equation (4)

If x=0,y=

3

2x−9

=

3

2(0)−9

=

3

−9

=−3

If x=6,y=

3

2(6)−9

=

3

12−9

=

3

3

=1

Plotting (0,−3),(6,1) and joining them, we get another straight line.

These lines intersect at the point (6,1) and therefore the solution of the equation is x=6,y=1 .

hope it's helpful

Answer 2

x+y=7

x-3=7

x=7+3=10

thank you