How do you solve $\sqrt{x^{2} + 8 x - 9} = x$ $sqrt(x^2+8x-9)=x$ ?

Question

How do you solve $\sqrt{x^{2} + 8 x - 9} = x$ $sqrt(x^2+8x-9)=x$ ?

3 Answers

Impact of this question

3128 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-03-10T13:51:10

$x = \frac{9}{8}$ $x=9/8$

Explanation:

$\sqrt{x^{2} + 8 x - 9} = x$ $sqrt(x^2+8x-9) = x$

Squaring both sides,
$x^{2} + 8 x - 9 = x^{2}$ $x^2+8x-9 = x^2$

Subtracting $x^{2}$ $x^2$ from both sides,
$8 x - 9 = 0$ $8x-9=0$
$8 x = 9$ $8x=9$
$x = \frac{9}{8}$ $x=9/8$

Answer 2 · 2018-03-10T13:52:04

$x = \frac{9}{8}$ $x=9/8$

Explanation:

$square both sides$ $color(blue)"square both sides"$

$\Rightarrow {(\sqrt{x^{2} + 8 x - 9})}^{2} = x^{2}$ $rArr(sqrt(x^2+8x-9))^2=x^2$

$rArrcancel(x^2)+8x-9=cancel(x^2)$

$rArr8x=9rArrx=9/8$

$color(blue)"As a check"$

$rArrsqrt((9/8)^2+8(9/8)-9)$

$=sqrt(81/64cancel(+9)cancel(-9))=9/8=" right side"$

$rArrx=9/8" is the solution"$

Answer 3 · 2018-03-10T13:52:40

$x=9/8$

Explanation:

We can square both sides of the equation.

$sqrt(x^2+8x-9)=x$

$x^2+8x-9=x^2$

$8x-9=0$

$8x=9$

$x=9/8$

Science

Math

Humanities

... and beyond

How do you solve $\sqrt{x^{2} + 8 x - 9} = x$ $sqrt(x^2+8x-9)=x$ ?

3 Answers

Explanation:

Explanation:

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

How do you solve sqrt(x^2+8x-9)=x√x2+8x−9=xsqrt(x^2+8x-9)=x?

3 Answers

Explanation:

Explanation:

Explanation:

Related questions

Impact of this question

How do you solve $\sqrt{x^{2} + 8 x - 9} = x$ $sqrt(x^2+8x-9)=x$ ?