If -6b+2a-25 = 5 and a/b + 6 = 4, what is the value of (b/a)square?

Question

1165 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-02-27T05:25:16

$-6b+2a-25 = 5$

$=>2a-6b = 30 => a-3b=15$

$=>a=3b+15 -> color(red)(1$

$color(white)(b=-3$

$a/b + 6 = 4$

$=>(3b+15 )/b + 6 = 4$ (Replacing $a$ from $color(red)(1)$ )

$=>3+15/b = -2$

$=>15/b=-5$

$=>color(magenta)(b=-3$

Now, coming to $a$ , $a=3b+15$
$=>a = 3(-3) +15$
$=>color(magenta)(a= 6$

To find ; $(b/a)^2 = (-3/6)^2 = (-1/2)^2 = 1/4$

$color(white)(b=-3$

Alternatively ,
Form the equation, $a/b + 6 = 4$

$a/b=-2$

$b/a=(-1)/2$

and then, squaring both the sides, we would get,

$(b/a)^2=((-1)/2)^2 = 1/4$

That's a comparatively shorter approach :)
Hope it helps.