which equation has (2 -1) as a solution?
A.y=2x - 1...
B.y=x + 3
C.y=x - 3
D.y=(-2x) + 1
To determine which equation has (2, -1) as a solution, we can substitute the values x = 2 and y = -1 into each equation and check if the resulting equation is true.
Let's start with option A:
A. y = 2x - 1
Substituting x = 2 and y = -1:
-1 = 2(2) - 1
-1 = 4 - 1
-1 = 3 (This is not true.)
Moving on to option B:
B. y = x + 3
Substituting x = 2 and y = -1:
-1 = 2 + 3
-1 = 5 (This is not true.)
Next, let's try option C:
C. y = x - 3
Substituting x = 2 and y = -1:
-1 = 2 - 3
-1 = -1 (This is true!)
Finally, we check option D:
D. y = (-2x) + 1
Substituting x = 2 and y = -1:
-1 = (-2)(2) + 1
-1 = -4 + 1
-1 = -3 (This is not true.)
Therefore, the equation with (2, -1) as a solution is option C, y = x - 3.
( 2 , - 1 )
mean x = 2 , y = - 1
for
A.
y = 2 x - 1
y = 2 ∙ 2 - 1 = 4 - 1 = 3
for
B.
y = x + 3 = 2 + 3 = 5
for
C.
y = x - 3 = 2 - 3 = - 1
for
D.
y = ( - 2 x ) + 1 = ( - 2 ∙ 2 ) + 1 = - 4 + 1 = - 3
Only equation C
y = x - 3
has solution
x = 2 , y = - 1
OR
( 2 , -1)