Question

Can any one solve me this by completing the square method. 4x^+17x=15. Plz I will mark u as brainliest

help

Answer 1

✪ᴀɴsᴡᴇʀ✪

$x = \frac{3}{4}\: or\: -5$

★ᴇxᴘʟᴀɪɴᴀᴛɪᴏɴ★

The given equation is

$\to 4x^2 + 17x = 15$

By completing square method,

$\to (2x)^2 + 2.2x.\frac{17}{4} +\left(\frac{17}{4}\right)^2$

$\:\:\:\:\:= 15 +\left(\frac{17}{4}\right)^2$

$\to \left(2x + \frac{17}{4}\right)^2= \left(\frac{240 + 289}{16}\right)$

$\to \left(2x + \frac{17}{4}\right)^2= \frac{529}{16}$

$\to \left(2x + \frac{17}{4}\right)=±\sqrt{\frac{23^2}{4^2}}$

$\to 2x + \frac{17}{4}=±\frac{23}{4}$

$\to 2x = - \frac{17}{4} ± \frac{23}{4}$

$\to 2x = \frac{-17+23}{4}\: or\: \frac{-17-23}{4}$

$\to 2x = \frac{6}{4}\: or\: \frac{-40}{4}$

$\to x = \frac{3}{4}\: or\: -5$

Thus, $\frac{3}{4}$ and $-5$ are the roots of the given equation.