Hello, dojo!

Your algebra went a little off . . .

. .

.Yes!

.Right!

. . .no

Substitute: .

. .

. . . . . . . . . . . .

Multiply by 9: .

Factor:. . . . . .

. . Hence: .

Since is further from . we have: .

Line has slope

The tangent at is perpendicular to

. . Hence, its slope is

The line through with slope is:

. . . . . .

Simplify: .

Multiply by 20: .

Divide by 5: .