Question

PLZ HELP I DONT UNDERSTAND (show steps)

Answer 1

Explanation:

perfect sqaure formula (u+w)²=u²+2uw+w²

ax²+bx+c=0 divide by a

`x^(2) +(bx)/(a) + (c)/(a) =0` so u=1, 2uw=2*1*w= b/a, so w=b/2a

`(x^(2)+ (bx)/(a) +(b^(2) )/(4a^(2) ) ) +(c)/(a) -(b^(2) )/(4a^(2) )=0` now that we formed the perfect sqare solve

`(x +(b)/(2a) )^(2) +(c*4*a-b^(2) )/(4a^(2) ) =0` but we can factor a negative in front of the fraction

`(x+(b)/(2a) )^(2) -(b^(2) -4ac )/(4a^(2) ) =0` now isolate the 2 terms and squareroot both sides

`\sqrt{ (x +(b)/(2a) )^(2)} =\sqrt{ (b^(2) -4ac )/(4a^(2) ) }` and you will be left with

`x +(b)/(2a) =\ + - \frac {\sqrt{ b^(2) -4ac} }{2a }` subtract b/2a from both sides

x=
`\frac{-b+ - \sqrt{b^(2)-4ac } }{2a}`

Answer 2

a= −b/x

Explanation:

Let's solve for a.

ax2+bx=0

Step 1: Add -bx to both sides.

ax2+bx+−bx=0+−bx

ax2=−bx

Step 2: Divide both sides by x^2.

ax2x2=−bxx2

a=−bx