The height of a triangle is 4 feet greater than 4 times its base. if the area of the triengle is 84ft^2, what is the height of the triangle?

Given: Area of triangle =84 square feet

height= 4 feet greater than 4 times its base

h=4b +4

Area of triangle= 1/2 ( b) (h)

plugging for area and height

84=1/2 ( b)* (4b+4)

168=4b² +4b

4b²+4b-168=0

taking out 4 common as gcf

b²+b-42=0

factorising we get

(b+7)(b-6)=0

b=6, -7

since length cannot be negative so base =6feet

height= 4b+4 = 24+4=28 feet

the two may have that, even a breakdown is probably offered

what is the answer?