Answer:
![a=3](https://img.qammunity.org/2020/formulas/mathematics/high-school/vvy5czbweakwzfwumlixp2vlfbydhcdi9e.png)
Explanation:
The correct question is
What is the value of a, if the point (a,7) lies on the line?
step 1
Find the equation of the line in point slope form
![y-y1=m(x-x1)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/38rsw060gekfjbf76g57jsb45ginj88wcy.png)
we have
![m=-3\\(x1,y1)=(6,-2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jw6s9vf9kj97v4yecxczu1k1sxq7flrngd.png)
substitute
----> equation in point slope form
step 2
Find the value of a
we know that
If a ordered pair lie on the line, then the ordered pair must satisfy the equation of the line
we have
(a,7)
substitute in the equation of the line
![7+2=-3(a-6)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/og20po6qlir5bw9xlgq1grrlqjodlu12wk.png)
![9=-3a+18](https://img.qammunity.org/2020/formulas/mathematics/middle-school/6423zbxwpgwgnshgrq0jiwb5wu1mvj5b2k.png)
Solve for a
![3a=18-9](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dxdc59rtrjkmwwlgf3ld52e7h7sumqy2oz.png)
![3a=9](https://img.qammunity.org/2020/formulas/mathematics/middle-school/uq466qwiuvvf0ob31ofrevxzcm9jhqte40.png)
![a=3](https://img.qammunity.org/2020/formulas/mathematics/high-school/vvy5czbweakwzfwumlixp2vlfbydhcdi9e.png)