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A student says that if 5x2 = 20, then x must be equal to 2. Do you agree or disagree with the student? Justify your answer.
I disagree. If each side of the equation is divided by 5, the result is x2 = 4. By the square root property of equality, x = -2 or x = 2. So x could be -2 instead of 2.

Respuesta :

I disagree. If each side of the equation is divided by 5, the result is x2 = 4. By the square root property of equality, x = -2 or x = 2. So x could be -2 instead of 2.
calculista

we have

[tex]5x^{2}=20[/tex]

solve for x

Divide by [tex]5[/tex] both sides

[tex]5x^{2}/5=20/5[/tex]

[tex]x^{2}=4[/tex]

square root both sides

[tex]\sqrt{x^{2}} =\sqrt{4}[/tex]

[tex]x=(+/-)2[/tex]

so

the solutions are

[tex]x1=2\\\\x2=-2[/tex]

therefore

the answer is

I disagree because x could be [tex]-2[/tex] instead of [tex]2[/tex].


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