Aladder is leaning against a building so that the distance from the ground to the top of the ladder is 3 feet
less than the length of the ladder. find the length of the ladder if the distance from the bottom of the ladder to
the building is 15 feet.

the length of the ladder is

39 feet

Step-by-step explanation:

From the question;

let length of ladder =x feet

height of ladder will be=x-3 feet

ground distance of ladder bottom to building=15 feet

Applying Pythagorean relation

a²+b²=c²

where a=15 feet b=x-3 feet and c=x feet thus

x²-15²=(x-3)²

x²-225=x²-6x+9

collect like term

x²-x²-225-9=-6x

-234= -6x

x= 39 feet length of ladder

distance from ground to top of ladder= 39-3=36 feet

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb

add an !

step-by-step explanation: