MikeDecorah MikeDecorah
  • 04-03-2015
  • Mathematics
contestada

Find the student’s error in solving the following inequality.
2 < –3x –4 < 5
6 < –3x < 5
–2 > x > –5/3

Respuesta :

naǫ
naǫ naǫ
  • 04-03-2015
The student didn't add 4 to all expressions in the inequality.
It should be:
[tex]2<-3x-4<5 \ \ \ |+4 \\ 6<-3x<9 \ \ \ |\div (-3) \\ -2>x>-3[/tex]
Answer Link
Panoyin
Panoyin Panoyin
  • 05-03-2015
2 < -3x - 4 < 2
+4        +4  +4
2 < -3x < 6
-2           -2
       -3x < 4
        -3    -3
          x < -1 1/3

6 < -3x < 5
-5           -5
1 < -3x
-3    -3
-1/3 < x
x > -1/3

-2 > x > -5/3
+5/3      +5/3
-1/3 > x
x < -1/3
Answer Link

Otras preguntas

Lim[(sqrt(cos(2x))-cubicrootof(cos(x))]/arctg(x^2) when x->0
Is economic equality an attainable goal?
Lim[(sqrt(cos(2x))-cubicrootof(cos(x))]/arctg(x^2) when x->0
Is the following correspondence a function
what value of a makes the equation true? 9a+2=4a-18
let f(x)=2x+2. solve f^-1(x) when x=4.
Helen Grey By Christina Georgina Rossetti Because one loves you, Helen Grey, Is that a reason you should pout, And like a March wind veer about, And frown, and
what is the GCF of 12x and 44xy
Helen Grey By Christina Georgina Rossetti Because one loves you, Helen Grey, Is that a reason you should pout, And like a March wind veer about, And frown, and
If a 35 ft rope is cut into two sections with one section 6 times as long as the other section, how long is the shorter piece?