How do you solve 7abs(10v-2)-9=5?

1 Answer
Mar 15, 2018

See a solution process below:

Explanation:

First, add color(red)(9) to each side of the equation to isolate the absolute value term while keeping the equation balanced:

7abs(10v - 2) - 9 + color(red)(9) = 5 + color(red)(9)

7abs(10v - 2) - 0 = 14

7abs(10v - 2) = 14

Next, divide each side of the equation by color(red)(7) to isolate the absolute value function while keeping the equation balanced:

(7abs(10v - 2))/color(red)(7) = 14/color(red)(7)

(color(red)(cancel(color(black)(7)))abs(10v - 2))/cancel(color(red)(7)) = 2

abs(10v - 2) = 2

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.

Solution 1:

10v - 2 = -2

10v - 2 + color(red)(2) = -2 + color(red)(2)

10v - 0 = 0

10v = 0

(10v)/color(red)(10) = 0/color(red)(10)

(color(red)(cancel(color(black)(10)))v)/cancel(color(red)(10)) = 0

v = 0

Solution 2:

10v - 2 = 2

10v - 2 + color(red)(2) = 2 + color(red)(2)

10v - 0 = 4

10v = 4

(10v)/color(red)(10) = 4/color(red)(10)

(color(red)(cancel(color(black)(10)))v)/cancel(color(red)(10)) = 2/5

v = 2/5

The Solution Set Is: v = {0, 2/5}