How to complete the square of 4x^2+10x-3=0

Question

How to complete the square of  4x^2+10x-3=0

anonymous · Answer

get x by it self homes

campbell_st · Answer

start by rewriting it as

$$4x^2 + 10x + ? = 3 + ?$$


and ? is the value of the constant in the perfect square that is added to both sides

Its important to know

$$ 4x^2 = (2x)^2  $$   

you need to know that 

$$(a + b)^2 = a^2 + 2ab + b^2 $$

so a = 2x

and 

2ab = 10x

so 

$$2 \times 2x \times b = 10x$$

you need to solve for b

then square the value and add it to both sides... 

does that make sense

wolf1728 · Answer

OR try tihs
4x^2+10x =3
Divide equation by the coefficient of x^2
x^2 + 2.5x = .75
get the coefficient of x which is 2.5
divide it by 2 which is 1.25
then square it
(1.25)^2 = 1.5625
and add it to both sides of the equation.
x^2 + 2.5x + 1.5625 = .75 + 1.5625

Taking the square root of both sides:
(x +1.25) = sqr root (2.3125)

(x + 1.25) = 1.5206906326
x = 0.2706906326

sqr root (2.3125) also equals -1.5206906326
(x + 1.25) = -1.5206906326
x = -2.7706906326

anonymous · Answer

its 8

wolf1728 · Answer

It is NOT 8.
Putting 8 into the original equation:
4x^2+10x-3=0
4*8* + 10*8 -3 ?=0
32 + 80 -3 = 109 and so 'x' does NOT =8

the answers are:
x = 0.2706906326
x = -2.7706906326