Answer:
(4) graph is correct.
Step-by-step 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.
