abs(2*x-1)+3=abs(5-x)+4
1) Let's solve in ℝ: abs(2x -1) + 3 = abs(5 -x) + 4
abs(2x -1) + 3 -abs(5 -x) -4 = 0
ⓘ Start from 3 and move back 4 on the number line, going below zero: 3 -4 = -1
abs(2x -1) -1 -abs(5 -x) = 0
The absolute-value arguments are zero at { 12, 5 }. Split ℝ at these points and solve on each interval
On (-∞, 12]: 2x -1 ≤ 0, so abs(2x -1) = -(2x -1) ; 5 -x ≥ 0, so abs(5 -x) = 5 -x
On (-∞, 12], the equation becomes -(2x -1) -1 -(5 -x) = 0
2) Let's solve in ℝ: -(2x -1) -1 -(5 -x) = 0
-2x + 1 -1 -5 + x = 0
ⓘ Start from 1 and move back 1 on the number line, down to zero: 1 -1 = 0■Like terms are grouped by adding their coefficients: -2x + x = -x
-x + 0 -5 = 0
ⓘ Adding 0 changes nothing: 0 -5 = -5
-x -5 = 0
ⓘ We add x to both sides
-5 = x
Solution obtained: x = -5
As -5 ≤ 12, we can keep the solution -5
On [12, 5]: 2x -1 ≥ 0, so abs(2x -1) = 2x -1 ; 5 -x ≥ 0, so abs(5 -x) = 5 -x
On [12, 5], the equation becomes (2x -1) -1 -(5 -x) = 0
3) Let's solve in ℝ: (2x -1) -1 -(5 -x) = 0
ⓘ Start from -1 and move back 1 more on the number line, away from zero: -1 -1 = -2■A minus sign before a parenthesis changes the sign of each of its terms: -(5 -x) = -5 + x
2x -2 -5 + x = 0
ⓘ Start from -2 and move back 5 more on the number line, away from zero: -2 -5 = -7■Like terms are grouped by adding their coefficients: 2x + x = 3x
3x -7 = 0
ⓘ We add 7 to both sides
3x = 7
ⓘ Both sides are divided by 3
Solution found: x = 73
As 73 ∈ [12, 5], we can keep the solution 73
On [5, +∞): 2x -1 ≥ 0, so abs(2x -1) = 2x -1 ; 5 -x ≤ 0, so abs(5 -x) = -(5 -x)
On [5, +∞), the equation becomes (2x -1) -1 + (5 -x) = 0
4) Let's solve in ℝ: (2x -1) -1 + (5 -x) = 0
ⓘ Start from -1 and move back 1 more on the number line, away from zero: -1 -1 = -2■Like terms are grouped by adding their coefficients: 2x -x = x
x -2 + 5 = 0
ⓘ Start from -2 and move forward 5 on the number line, going past zero: -2 + 5 = 3
x + 3 = 0
ⓘ We subtract 3 from both sides
Solution obtained: x = -3
As -3 ∉ [5, +∞), we cannot keep the solution -3
▶Solutions obtained: x = { -5, 73 }
5) The numeric value of: x = { -5, 73 } is:
▷ x = { -5, ≈ 2.3333 }