SOLUTION: Please help, A triangular area is 12 sq. ft. Find the base of the triangular area if the height is 1 ft. less than the base. I tried let b = base, h(height)=b-1 12=1/2b(b-1) (1

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Please help, A triangular area is 12 sq. ft. Find the base of the triangular area if the height is 1 ft. less than the base. I tried let b = base, h(height)=b-1 12=1/2b(b-1) (1      Log On


   

Question 300049: Please help, A triangular area is 12 sq. ft. Find the base of the triangular area if the height is 1 ft. less than the base. I tried
let b = base, h(height)=b-1
12=1/2b(b-1)
(12)2=(1/2)2(b)2(b-1)2
24=4b-2
then im lost
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A triangular area is 12 sq. ft.
Find the base of the triangular area if the height is 1 ft. less than the base.
:
12=1/2b(b-1)
(12)2=(1/2)2(b)2(b-1)2
Right here you should have:
24 = b^2 - b
b^2 - b - 24 = 0; a quadratic equation
This will not factor, use the quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
in this equation, x=b; a=1; b=-1; c=-24
b+=+%28-%28-1%29+%2B-+sqrt%28-1%5E2-4%2A1%2A-24+%29%29%2F%282%2A1%29+
:
b+=+%281+%2B-+sqrt%281+-+%28-96%29+%29%29%2F2+
:
b+=+%281+%2B-+sqrt%2897+%29%29%2F2+
positive solution
b+=+%281+%2B+9.85%29%2F2+
b = 10.85%2F2
b = 5.42 ft is the base
and
4.42 ft is the height
:
:
Check solution by finding the area
A = 1%2F2*5.42*4.42
A = 11.97 ~ 12