Finding the Constant a for a Given Point on a Linear Equation

[mathdad]

You are given an equation and a point. In each case, find the value of the constant a so that the graph of the equation passes through the given point.

y = -5x - a; (-4, 1)

Solution:

Let x = -4 and y = 1

y = -5x - a

1 = -5(-4) - a

1 = 20 - a

1 - 20 = - a

-19 = -a

-19/-1 = a

19 = a

Correct?

 

[kaliprasad]

You are given an equation and a point. In each case, find the value of the constant a so that the graph of the equation passes through the given point.

y = -5x - a; (-4, 1)

Solution:

Let x = -4 and y = 1

y = -5x - a

1 = -5(-4) - a

1 = 20 - a

1 - 20 = - a

-19 = -a

-19/-1 = a

19 = a

Correct?

The answer is right. to check the correctness of the result you can put the value and check

$y= -5x - 19$ and at $x = -4 $ we get $y= - 5 * (-4) -19 = 20-19 =1$ which is true

 

[mathdad]

Very interesting. I will do likewise for the other question.