The difference between the roots of the equation 2x2−5x+c=0 is 0.25. Find c.

c = 3.09375

Step-by-step explanation:

let the roots be α  and β

2x2−5x+c=0

Comparing withe the standard equation ax² + bx + c = 0

a=2   b = -5   and  c=c

sum : α + β =

product : αβ  =  

α + β =  =   = 2.5 -------------------------------------(1)

αβ =   -----------------------------------------------------------(2)

the question says "the difference between the roots of the equation is  0.25"

so, α -β = 0.25 ---------------------------------------------------(3)

we can use equation (1)  and equation (3) to find the values of our  α  and β by solving simultaneously

add equation  (1)   and equation (3)  

2 α  = 2.75

α = 2.75 /2  = 1.375

subtract equation (3)   from equation (1)

2β = 2.25

β = 2.25 /2 = 1.125

we can now use equation (2) to find the value of c

αβ =

1.375 × 1.125  =  

1.546875 =  

multiply both-side of the equation by 2

1.546875 × 2 = c

3.09375 = c

c = 3.09375

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1

step-by-step explanation: