Question

for each ordered pair, determine whether it is a solution to $7x + 4y = -23$.

$(x, y)$	is it a solution?
$(6, -7)$	$circ$	$circ$
$(-1, -4)$	$circ$	$circ$
$(2, 6)$	$circ$	$circ$
$(-5, 3)$	$circ$	$circ$

Explanation:

for (6, -7):

Step1: Substitute x=6, y=-7 into 7x + 4y

$7\times6 + 4\times(-7)$

Step2: Calculate the result

$42 - 28 = 14
eq -23$
So (6, -7) is not a solution.

for (-1, -4):

Step1: Substitute x=-1, y=-4 into 7x + 4y

$7\times(-1) + 4\times(-4)$

Step2: Calculate the result

$-7 - 16 = -23$
So (-1, -4) is a solution.

for (2, 6):

Step1: Substitute x=2, y=6 into 7x + 4y

$7\times2 + 4\times6$

Step2: Calculate the result

$14 + 24 = 38
eq -23$
So (2, 6) is not a solution.

for (-5, 3):

Step1: Substitute x=-5, y=3 into 7x + 4y

$7\times(-5) + 4\times3$

Step2: Calculate the result

$-35 + 12 = -23$
So (-5, 3) is a solution.

Answer:

• (6, -7): No
• (-1, -4): Yes
• (2, 6): No
• (-5, 3): Yes