Respuesta :
Answer:
a) The possible solutions are:
x=7 and x=-3
b)The extraneous solution
is x=
Step-by-step explanation:
The last step gives us the possible solutions.
[tex](x + 3)(x - 7) = 0[/tex]
By the zero product property,
[tex]x + 3 = 0 \: or \: x - 7 = 0[/tex]
This implies that:
[tex]x = - 3 \: or \: x = 7[/tex]
The original equation is
[tex] \sqrt{30 - 2x} = x - 3[/tex]
We substitute x=-3 to get;
[tex]\sqrt{30 - 2 \times - 3} = - 3 - 3 \\ \sqrt{30 + 6} = - 6 \\ \sqrt{36} = - 6 \\ 6 = - 6 [/tex]
This not true, therefore x=-3 is an extraneous solution.
We substitute x=7
[tex]\sqrt{30 - 2 \times 7} = 7- 3 \\ \sqrt{30 - 14} = 4 \\ \sqrt{16} = 4 \\ 4 = 4[/tex]
Therefore x=7 is the only solution.
The possible solutions are -3 and 7, and the extraneous solution is x = -3,
From the steps shown, the last step is:
[tex]0 = (x + 3)(x - 7)[/tex]
Rewrite as:
[tex](x + 3)(x - 7)=0[/tex]
Split
[tex](x + 3)=0\ or\ (x - 7)=0[/tex]
Remove brackets
[tex]x + 3=0\ or\ x - 7=0[/tex]
Solve for x
[tex]x =-3\ or\ x =7[/tex]
So, the possible solutions are -3 and 7
Substitute -3 and 7 for x in the original equation to determine the extraneous solution.
[tex]\sqrt{30 - 2x}= x - 3[/tex]
[tex]\sqrt{30 - 2(-3)}= -3 - 3[/tex]
[tex]\sqrt{36}= -6[/tex]
Take square root of 36
[tex]6= -6[/tex]
[tex]\sqrt{30 - 2x}= x - 3[/tex]
[tex]\sqrt{30 - 2(7)}= 7- 3[/tex]
[tex]\sqrt{16}= 4[/tex]
Take square root of 16
[tex]4= 4[/tex]
Hence, the extraneous solution is x = -3, because [tex]6 \ne -6[/tex]
Read more about extraneous solutions at:
https://brainly.com/question/2959656