Question

Choose the graph that matches the following system of equations:

7x + 2y = −6
6x − 7y = 21

Answer 1

it's the lasts graph it intersects at 0,-3

Answer 2

(4) graph is correct.

Explanation:

Given: the following system of equations:

7x + 2y = −6

6x − 7y = 21

We have to choose the correct graph for the given system of equations.

Consider the given system of equations:

7x + 2y = −6 .....(1)

6x − 7y = 21 .........(2)

Multiply (1) by 7 and (2) by 2 , we have,

( 7x + 2y = -6 ) × 7 , we have,

49x + 14y = - 42 ........(3)

( 6x − 7y = 21 ) × 2 , we have,

12x − 14y = 42 .............(4)

Add (3) and (4) , we have,

49x + 14 y + (12x - 14y)= - 42 + 42

49x + 12x = 0

x = 0

Put in (1) , we have,

7(0) + 2y = −6 ⇒ 2y = -6 ⇒ y = -3

Thus, (0, -3) is the solution.

So, (4) graph is correct.