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Answer 1 · 2017-10-11T03:22:36

$x=9/3$

Given -

$9x^2-25=0$

$9x^2=25$

$x^2=25/9$
$x=sqrt(25/9)$
$x=sqrt25/sqrt9=5/3$
$x=9/3$

Answer 2 · 2017-10-11T03:27:07

$x=\frac{5}{3},\qquad\qquad x=-\frac{5}{3}$

This is the standard form of a quadratic equation, which we can find the roots of by using the quadratic formula.

Rewriting the equation:

$9x^2+0x-25=0$

Our values to plug into the formula are:

The formula is:

$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

Plugging in for the variables:

$x=\frac{0\pm\sqrt{0^2-4(9)(-25)}}{2(9)}$

$x=\frac{0\pm\sqrt{0+900}}{18}$

$x=\frac{0\pm\sqrt{900}}{18}$

$x=\frac{0\pm 30}{18}$

$x=\frac{15}{18},\qquad\qquad x=-\frac{30}{18}$

$\therefore x=\frac{5}{3},\qquad\qquad x=-\frac{5}{3}$