Answer:
![y=-(1)/(3)x+7](https://img.qammunity.org/2019/formulas/mathematics/middle-school/qz71fr7x11niedxk765vl7s76qx564vujv.png)
Explanation:
The slope-intercept form is:
; where m is the slope, and b is the y-axis interception.
So, the problem is asking for a line that it's perpendicular to
. This perpendicular relation means that the line we have to find have an inverse and opposite slope than the given line, that's expressed like this:
![m_(1)m_(2)=-1](https://img.qammunity.org/2019/formulas/mathematics/middle-school/xlpf8f834fk56zupn2v5weiweritsqcpxy.png)
That expression is the condition to have perpendicular lines. So, the given line has a slope of 3, now we can find the slope of the new line:
![m_(1)m_(2)=-1\\m_(1)=(-1)/(m_(2))=-(1)/(3)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/nku5nl0cxc30innv1c7z5ueo2749hwoha4.png)
Now we have the slope of the new perpendicular line, we use the point-slope formula to find its equation:
![y-y_(1)=m(x-x_(1))\\ y-7=-(1)/(3)(x-0)\\y=-(1)/(3)x+7](https://img.qammunity.org/2019/formulas/mathematics/middle-school/ibt0k9oxujifv6prpzine1tl3wfyxqqow4.png)
Therefore, the slope-intercept form of the new perpendicular line is:
![y=-(1)/(3)x+7](https://img.qammunity.org/2019/formulas/mathematics/middle-school/qz71fr7x11niedxk765vl7s76qx564vujv.png)