Question

if the point -2,4 lies on the graph of the equation y=ax+5 then find the value of a

Answer 1

Since, the point (-2,4) lie in second quadrant,
Hence x = -2 & y = 4

Y = ax + 5
4 = a(-2) + 5
4 = -2a + 5
2a = 5 - 4
2a = 1
a = 1/2

Hence, a = 1/2

Answer 2

If the point (-2, 4) lies on the graph of y = ax + 5, then the value of a is 0.5.

Given,

The point (-2, 4), lies on the graph of y = ax + 5.

To find,

The value of a.

Solution,

Here, we can see that the point (-2, 4) is given to be lying on the line having equation

y = ax + 5     ...(1)

Now, we know that when a point lies on a line, or the line passes through a point, then the point satisfies the equation of the line.

It means substituting the point in the equation must satisfy the equation.

So, putting (-2, 4) in (1), we get,

4 = a(-2) + 5

⇒ 4 = -2a + 5

Rearranging and simplifying,

2a = 5 - 4

⇒ 2a = 1

$\implies a =\frac{1}{2} =0.5$

⇒ a = 0.5.

Therefore, if the point (-2, 4) lies on the graph of y = ax + 5, then the value of a is 0.5.

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