How do you solve #3=-2|1/4s-5|+3#?

2 Answers
Aug 13, 2017

#s=color(red)(20)#

Explanation:

#3=-2abs(1/4s-5)+3#

#rarr0=-2abs(1/4s-5)#

#rarr abs(1/4s-5)=0#

#rarr 1/4s=5#

#rarr s=20#

Aug 13, 2017

See a solution process below:

Explanation:

First, subtract #color(red)(3)# from each side of the equation to isolate the absolute value term while keeping the equation balanced:

#3 - color(red)(3) = -2abs(1/4s - 5) + 3 - color(red)(3)#

#0 = -2abs(1/4s - 5) + 0#

#0 = -2abs(1/4s - 5)#

Next, divide each side of the equation by #color(red)(-2)# to isolate the absolute value function while keeping the equation balanced:

#0/color(red)(-2) = (-2abs(1/4s - 5))/color(red)(-2)#

#0 = (color(red)(cancel(color(black)(-2)))abs(1/4s - 5))/cancel(color(red)(-2))#

#0 = abs(1/4s - 5)#

The absolute value function takes any term and transforms it to its non-negative form. Therefore, we must solve the term within the absolute value function for both its negative and positive equivalent. However, because #-0# equals #0# we can just solve the term within the absolute value function once for #0#:

#0 = 1/4s - 5#

Add #color(red)(5)# to each side of the equation to isolate the #s# term while keeping the equation balanced:

#0 + color(red)(5) = 1/4s - 5 + color(red)(5)#

#5 = 1/4s - 0#

#5 = 1/4s#

Now, multiply each side of the equation by #color(red)(4)# to solve for #s# while keeping the equation balanced:

#color(red)(4) xx 5 = color(red)(4) xx 1/4s#

#20 = cancel(color(red)(4)) xx 1/color(red)(cancel(color(black)(4)))s#

#20 = s#

#s = 20#