Masukkan persamaan atau masalah
Input kamera tidak dikenali!

Penyelesaian - Absolute value equations

Exact form: r=3,12
r=3 , \frac{1}{2}
Decimal form: r=3,0.5
r=3 , 0.5

Other Ways to Solve

Absolute value equations

Penjelasan langkah demi langkah

1. Rewrite the equation without absolute value bars

Use the rules:
|x|=|y|x=±y and |x|=|y|±x=y
to write all four options of the equation
|r+2|=|3r4|
without the absolute value bars:

|x|=|y||r+2|=|3r4|
x=+y(r+2)=(3r4)
x=y(r+2)=(3r4)
+x=y(r+2)=(3r4)
x=y(r+2)=(3r4)

When simplified, equations x=+y and +x=y are the same and equations x=y and x=y are the same, so we end up with only 2 equations:

|x|=|y||r+2|=|3r4|
x=+y , +x=y(r+2)=(3r4)
x=y , x=y(r+2)=(3r4)

2. Solve the two equations for r

13 additional steps

(r+2)=(3r-4)

Subtract from both sides:

(r+2)-3r=(3r-4)-3r

Kumpulkan sebutan sejenis:

(r-3r)+2=(3r-4)-3r

Permudahkan aritmetik:

-2r+2=(3r-4)-3r

Kumpulkan sebutan sejenis:

-2r+2=(3r-3r)-4

Permudahkan aritmetik:

2r+2=4

Subtract from both sides:

(-2r+2)-2=-4-2

Permudahkan aritmetik:

2r=42

Permudahkan aritmetik:

2r=6

Divide both sides by :

(-2r)-2=-6-2

Hapuskan tanda negatif:

2r2=-6-2

Permudahkan pecahan:

r=-6-2

Hapuskan tanda negatif:

r=62

Cari faktor sepunya terbesar bagi pembilang dan penyebut:

r=(3·2)(1·2)

Faktorkan keluar dan hapuskan faktor sepunya terbesar:

r=3

12 additional steps

(r+2)=-(3r-4)

Expand the parentheses:

(r+2)=-3r+4

Add to both sides:

(r+2)+3r=(-3r+4)+3r

Kumpulkan sebutan sejenis:

(r+3r)+2=(-3r+4)+3r

Permudahkan aritmetik:

4r+2=(-3r+4)+3r

Kumpulkan sebutan sejenis:

4r+2=(-3r+3r)+4

Permudahkan aritmetik:

4r+2=4

Subtract from both sides:

(4r+2)-2=4-2

Permudahkan aritmetik:

4r=42

Permudahkan aritmetik:

4r=2

Divide both sides by :

(4r)4=24

Permudahkan pecahan:

r=24

Cari faktor sepunya terbesar bagi pembilang dan penyebut:

r=(1·2)(2·2)

Faktorkan keluar dan hapuskan faktor sepunya terbesar:

r=12

3. List the solutions

r=3,12
(2 solution(s))

4. Graph

Each line represents the function of one side of the equation:
y=|r+2|
y=|3r4|
The equation is true where the two lines cross.

Mengapa belajar ini

Learn more with Tiger

We encounter absolute values almost daily. For example: If you walk 3 miles to school, do you also walk minus 3 miles when you go back home? The answer is no because distances use absolute value. The absolute value of the distance between home and school is 3 miles, there or back.
In short, absolute values help us deal with concepts like distance, ranges of possible values, and deviation from a set value.