1.Using the method of completion of squares find one of the roots of the equation 2x^2−7x+3=0. Also, find the equation obtained after completion of the square.3, (x−7/4)^2−25/16=0
class 10th math
Answers
SOLUTION :
Given : 2x² –7x + 3 = 0
On dividing the whole equation by 2,
(x² - 7x/2 + 3/2) = 0
Shift the constant term on RHS
x² - 7x/2 = - 3/2
Add square of the ½ of the coefficient of x on both sides
On adding (½ of 7/2)² = (7/4)² both sides
x² - 7x/2 + (7/4)²= - 3/2 + (7/4)²
Write the LHS in the form of perfect square
(x - 7/4)² = - 3/2 + 49/16
[a² - 2ab + b² = (a - b)²]
(x - 7/4)² = (-3 × 8 + 49)/16
(x - 7/4)² = (-24 + 49)/16
(x - 7/4)² = 25/16
On taking square root on both sides
(x - 7/4) = √(25/16)
(x - 7/4) = ± 5/4
On shifting constant term (-7/4) to RHS
x = ± 5/4 + 7/4
x = 5/4 + 7/4
[Taking +ve sign]
x = (5 +7)/4
x = 12/4
x = 3
x = - 5/4 + 7/4
[Taking -ve sign]
x = (- 5 + 7)/4
x = 2/4
x = 1/2
Hence, the roots of the given equation are 3 & ½.
HOPE THIS ANSWER WILL HELP YOU...
Step-by-step explanation:
To solve 2x2 - 7x + 3 = 0 using completing square method
2x^2-7x=-3
2x^2-7x=-3X^2-7x/2=-3/2
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2(X-7/4)^2=-3/2+49/16
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2(X-7/4)^2=-3/2+49/16(X-7/4)^2=25/16
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2(X-7/4)^2=-3/2+49/16(X-7/4)^2=25/16X-7/4=+or -5/4
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2(X-7/4)^2=-3/2+49/16(X-7/4)^2=25/16X-7/4=+or -5/4x=+5/4+7/4
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2(X-7/4)^2=-3/2+49/16(X-7/4)^2=25/16X-7/4=+or -5/4x=+5/4+7/4X=12/4=3
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2(X-7/4)^2=-3/2+49/16(X-7/4)^2=25/16X-7/4=+or -5/4x=+5/4+7/4X=12/4=3Also
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2(X-7/4)^2=-3/2+49/16(X-7/4)^2=25/16X-7/4=+or -5/4x=+5/4+7/4X=12/4=3AlsoX=-5/4+7/4
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2(X-7/4)^2=-3/2+49/16(X-7/4)^2=25/16X-7/4=+or -5/4x=+5/4+7/4X=12/4=3AlsoX=-5/4+7/42/4=1/2
2x^2-7x=-3X^2-7x/2=-3/2X^2-2x1/2x7x/2=-3/2X^2-2x1/2x7x/2+(7/4)^2=-3/2+(7/4)^2(X-7/4)^2=-3/2+49/16(X-7/4)^2=25/16X-7/4=+or -5/4x=+5/4+7/4X=12/4=3AlsoX=-5/4+7/42/4=1/2Hence x=3 and 1/2
- sorry for the complexity pls don't report