Order the steps to solve the equation log3(x + 2) = log3(2x^2 − 1) from 1 to 6.
0 = (2x − 3)(x + 1)
0 = 2x^2 − x −3
Potential solutions are −1 and 3/2
2x − 3 = 0 or x + 1 = 0
x + 2 = 2x^2 − 1
3^log3(x + 2) = 3^log3(2x2 − 1)

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frika

Consider the equation [tex]\log_3(x + 2)=\log_3(2x^2-1).[/tex]

1 step (option 6): rise 3 to the power of left and right sides

[tex]3^{\log_3(x + 2)}=3^{\log_3(2x^2-1)},\\ \\x+2=2x^2-1.[/tex]

Thus, you get equation from option 5.

2 step (option 2): rewrite the equation in one side

[tex]2x^2-x-2-1=0,\\ \\2x^2-x-3=0.[/tex]

3 step (option 1): factor the previous equation

[tex]D=(-1)^2-4\cdot 2\cdot (-3)=25,\ \sqrt{D}=5,\\ \\x_1=\dfrac{1-5}{4}=-1,\ x_2=\dfrac{1+5}{4}=\dfrac{3}{2},\\ \\2x^2-x-3=2\left(x-\dfrac{3}{2}\right)(x+1)=(2x-3)(x+1).[/tex]

Then the equatios becomes

[tex](2x-3)(x+1)=0.[/tex]

4 step (option 4): If product is equal to zero, then either [tex]2x-3=0[/tex] or [tex]x+1=0.[/tex]

5 step (option 3): Then Potential solutions are −1 and 3/2. You can check them substituting into the initial equation:

for [tex]x=-1:[/tex] [tex]\log_3(-1+ 2)=\log_31=0,\\ \\ \log_3(2\cdot (-1)^2-1)=\log_3 1=0.[/tex]

for [tex]x=\dfrac{3}{2}:[/tex] [tex]\log_3\left(\dfrac{3}{2}+ 2\right)=\log_3\dfrac{7}{2},\\ \\ \log_3(2\cdot \left(\dfrac{3}{2}\right)^2-1)=\log_3 \dfrac{7}{2}.[/tex]

Both are roots.

Answer: correct order of steps is 6, 5, 2, 1, 4, 3.

on Edg. the order of the answers would be 4,3,6,5,2,1


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