The polynomial which is in the form of ax2 + bx + c is known as quadratic polynomial. Here b or c may be 0 some times.
There are two types,
To solve quadratic equation, we follow different ways.
ii) Using quadratic formula
iii) Completing the square
Problem 1 :
4x2 - 9 = 0
Solution:
4x2 - 9 = 0
4x2 = 9
x2 = 9/4
x = ± 3/2
So, the solutions are {3/2, -3/2}.
Problem 2 :
2x2 + 4x + 1 = 0
Solution:
Comparing 2x2 + 4x + 1 = 0 and ax2 + bx + c = 0, we get
a = 2, b = 4 and c = 1
By using quadratic formula,
Problem 3 :
3x2 - x - 1 = 0
Solution:
Comparing 3x2 - x - 1 = 0 and ax2 + bx + c = 0, we get
a = 3, b = -1 and c = -1
By using quadratic formula,
Problem 4 :
2x2 - 5x + 1 = 0
Solution:
Comparing 2x2 - 5x + 1 = 0 and ax2 + bx + c = 0, we get
a = 2, b = -5 and c = 1
By using quadratic formula,
Problem 5 :
2x2 + 6x + 4 = 0
Solution:
2x2 + 6x + 4 = 0
2x2 + 4x + 2x + 4 = 0
2x(x + 2) + 2(x + 2) = 0
(x + 2) (2x + 2) = 0
Equating each factor to 0, we get
x + 2 = 0 and 2x + 2 = 0
x = -1 or x = -2
So, the solutions are x = -1 or x = -2.
Problem 6 :
3x2 + 15x + 18 = 0
Solution:
3x2 + 15x + 18 = 0
3x2 + 6x + 9x + 18 = 0
3x(x + 2) + 9(x + 2) = 0
(x + 2)(3x + 9) = 0
Equating each factor to zero, we get
x + 2 = 0 and 3x + 9 = 0
x = -2 and 3x = -9
x = -3
So, the solutions are x = -3 or x = -2.
Problem 7 :
2x2 - 6x - 8 = 0
Solution:
2x2 - 6x - 8 = 0
2(x2 - 3x - 4) = 0
2(x2 + x - 4x - 4) = 0
2(x(x + 1) - 4(x + 1)) = 0
2(x - 4) (x + 1) = 0
x - 4 = 0 or x + 1 = 0
x = 4 or x = -1
So, the solutions are x = 4 or x = -1.
Problem 8 :
x2 = 6x + 27
Solution:
x2 - 6x - 27 = 0
x2 - 9x + 3x - 27 = 0
x(x - 9) + 3(x - 9) = 0
(x + 3) (x - 9) = 0
x + 3 = 0 or x - 9 = 0
x = -3 or x = 9
So, the solutions are x = -3 or x = 9.
Problem 9 :
x2 = 13x - 36
Solution:
x2 - 13x + 36 = 0
x2 - 9x - 4x + 36 = 0
x(x - 9) - 4(x - 9) = 0
(x - 4) (x - 9) = 0
x - 4 = 0 or x - 9 = 0
x = 4 or x = 9
So, the solutions are x = 4 or x = 9.
Problem 10 :
2x2 - 5x = 12
Solution:
2x2 - 5x - 12 = 0
2x2 + 3x - 8x - 12 = 0
x(2x + 3) - 4(2x + 3) = 0
(x - 4) (2x + 3) = 0
x - 4 = 0 or 2x + 3 = 0
x = 4 or 2x = -3
x = -3/2
So, the solutions are x = 4 or x =-3/2.
Problem 11 :
2 = 9x - 5x2
Solution:
5x2 - 9x + 2 = 0
Comparing 5x2 - 9x + 2 = 0 and ax2 + bx + c = 0, we get
a = 5, b = -9 and c = 2
By using quadratic formula,
May 21, 24 08:51 PM
May 21, 24 08:51 AM
May 20, 24 10:45 PM