Masukkan persamaan atau masalah
Input kamera tidak dikenali!

Penyelesaian - Absolute value equations

Exact form: x=1,-75
x=1 , -\frac{7}{5}
Mixed number form: x=1,-125
x=1 , -1\frac{2}{5}
Decimal form: x=1,1.4
x=1 , -1.4

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
|7x+1|=|2x8|
without the absolute value bars:

|x|=|y||7x+1|=|2x8|
x=+y(7x+1)=(2x8)
x=y(7x+1)=(2x8)
+x=y(7x+1)=(2x8)
x=y(7x+1)=(2x8)

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||7x+1|=|2x8|
x=+y , +x=y(7x+1)=(2x8)
x=y , x=y(7x+1)=(2x8)

2. Solve the two equations for x

12 additional steps

(-7x+1)=(2x-8)

Subtract from both sides:

(-7x+1)-2x=(2x-8)-2x

Kumpulkan sebutan sejenis:

(-7x-2x)+1=(2x-8)-2x

Permudahkan aritmetik:

-9x+1=(2x-8)-2x

Kumpulkan sebutan sejenis:

-9x+1=(2x-2x)-8

Permudahkan aritmetik:

9x+1=8

Subtract from both sides:

(-9x+1)-1=-8-1

Permudahkan aritmetik:

9x=81

Permudahkan aritmetik:

9x=9

Divide both sides by :

(-9x)-9=-9-9

Hapuskan tanda negatif:

9x9=-9-9

Permudahkan pecahan:

x=-9-9

Hapuskan tanda negatif:

x=99

Permudahkan pecahan:

x=1

12 additional steps

(-7x+1)=-(2x-8)

Expand the parentheses:

(-7x+1)=-2x+8

Add to both sides:

(-7x+1)+2x=(-2x+8)+2x

Kumpulkan sebutan sejenis:

(-7x+2x)+1=(-2x+8)+2x

Permudahkan aritmetik:

-5x+1=(-2x+8)+2x

Kumpulkan sebutan sejenis:

-5x+1=(-2x+2x)+8

Permudahkan aritmetik:

5x+1=8

Subtract from both sides:

(-5x+1)-1=8-1

Permudahkan aritmetik:

5x=81

Permudahkan aritmetik:

5x=7

Divide both sides by :

(-5x)-5=7-5

Hapuskan tanda negatif:

5x5=7-5

Permudahkan pecahan:

x=7-5

Pindahkan tanda negatif dari penyebut ke pembilang:

x=-75

3. List the solutions

x=1,-75
(2 solution(s))

4. Graph

Each line represents the function of one side of the equation:
y=|7x+1|
y=|2x8|
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.