Which of the following equations have the same solution? Give reasons for your answer that do not depend on solving the equations.
A. -(7-4x)=9

B. 12=-4(-6x-3)

C. 5x+34=-2(1-7x)

D. 14=-(x-8)

E. -8=-(x+4)

F. x+5=-5x+5

Respuesta :

Answer:

A,C and E are equal with 4 as their solution; F and B are equal with 0 as their solution. D is independent.

Solution:

A. [tex]-(7-4x)=9[/tex]

Taking off the brackets we get,

[tex]-7+4x=9 \Rightarrow +4x=9+7[/tex]

[tex]\Rightarrow 4x=16 \\[/tex]

[tex]\Rightarrow x=\frac{16}{4} \Rightarrow 4[/tex]

Here x=4 --- (a)

B. [tex]12=-4(-6x-3)[/tex]

Multiplying -4 inside we get,

[tex]12=+24x+12 \Rightarrow 12-12=24x[/tex]

[tex]\Rightarrow x=0[/tex]

Here x=0 --- (b)

C. [tex]5x+34=-2(1-7x)[/tex]

Multiplying -2 inside we get,

[tex]5x+34=-2+14x[/tex]

Grouping the terms,

[tex]34+2=14x-5x \Rightarrow 36=9x[/tex]

[tex]\Rightarrow x=4[/tex]

Here x=4 --- (c)

D. [tex]14=-(x-8)[/tex]

[tex]\Rightarrow 14=-x+8 \Rightarrow -x=14-8[/tex]

[tex]\Rightarrow x=-6[/tex]

Here x=-6 --- (d)

E. [tex]-8=-(x+4)[/tex]

[tex]\Rightarrow -8=-x-4 \Rightarrow x=8-4[/tex]

[tex]\Rightarrow x=4[/tex]

Here x=4 --- (e)

F. [tex]x+5=-5x+5[/tex]

[tex]\Rightarrow x+5x=5-5[/tex]

[tex]6x=0 \Rightarrow x=0[/tex]

Here x=0 --- (f)

So, from the above calculations we can conclude that (a), (c) and (e) are equal and (f) and (b) are equal but (d) is independent because it has a different solution.