Answer:
a = - 1
Explanation:
Since ( 1 , -1) is a point on the line 2x-(2a+5)y=5 we can substitute it into the equation to find a
We have
2(1) - (-1)(2a + 5) = 5
Multiplying two negatives make a positive
That's
2 + 2a + 5 = 5
2a + 7 = 5
Group like terms
Send the constants to the right side of the equation
That's
2a = 5 - 7
2a = - 2
Divide both sides by 2
That's
We have the final answer as
a = - 1
Hope this helps you