Answer:
The solutions of the equation are -1 , -9
Step-by-step explanation:
* Lets explain how to solve the problem
- The absolute value of a number is the positive value only
- Ex: If IxI = 5, then x = 5 OR x = -5
* Lets solve the problem
∵ The equation is -4 Ix + 5I = -16
- At first divide both side by -4
∴ Ix + 5I = 4
∵ Ix + 5I = 4
∴ x + 5 = 4 OR x + 5 = -4
∵ x + 5 = 4
- Subtract 5 from both sides
∴ x = -1
∵ x + 5 = -4
- Subtract 5 from both sides
∴ x = -9
* Lets check the answer
∵ x = -1
∵ The left hand side of the equation is -4 Ix + 5I
∴ -4 I-1 + 5I = -4 I4I
∵ I4I = 4
∴ -4 × 4 = -16
∵ The right hand side of the equation is -16
∴ x = -1 is a solution of the equation
∵ x = -9
∵ The left hand side of the equation is -4 Ix + 5I
∴ -4 I-9 + 5I = -4 I-4I
∵ I-4I = 4
∴ -4 × 4 = -16
∵ The right hand side of the equation is -16
∴ x = -9 is a solution of the equation
∴ The solutions of the equation are -1 , -9
