Question

Free cookies Just answer this question! Elena solves the equation x^2=7x by dividing both sides by x to get 7. She says
the solution is 7. Lin solves the equation x^2=7 by rewriting the equation to get
x^2-7=0. When she graphs the equation x^2-7=0, the x-intercepts are (0,0) and
(7,0). She says the solutions are 0 and 7. Why should Elena not divide by x?

Answer 1

x could be equal to zero, and we can't divide by zero, so we shouldn't divide by x.

Why should Elena not divide by x?

Here we have the quadratic equation:

$x^2 = 7x$

Notice that we don't know the value of x, so technically, x could be equal to zero, and we can't divide by zero, so we shouldn't divide by x.

The quadratic equation can be rewritten as:

x^2 - 7x = 0

x*(x - 7) = 0

(x - 0)*(x - 7) = 0

So the two solutions are x = 0 and x = 7, because x = 0 is a solution, we see that x can be equal to zero, so we can't divide by x.

If you want to learn more about quadratic equations:

https://brainly.com/question/1214333

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