Слайд 21 way(Factoring the left side)
solve the equation:
8х2 + 10х +3 = 0
8х2 +
10х +3 = 8х2 + 4х +6х +3 = 4х(2х + 1) +3(2х + 1) = =(2х + 1)(4х +3)
(2х + 1)(4х +3)=0
2х + 1= 0 или 4х +3=0
2x=-1 4x=-3
x=-1/2 x=-3/4
х=-0,5 х=-0,75
Answer: -0,5; -0,75.
Слайд 32 way(Derivation of a formula for solving a quadratic equation)
solve the equation:
ax2 + bx + c=0
ax2 + bx = -c
(2ax)2 + 4abx = - 4ac
(2ax) 2 + 4abx + b2 = b2 - 4ac
(2ax + b) 2 = b2 - 4ac
2ax + b = ± √(b2 - 4ac)
2ax = - b ± √(b2 - 4ac)
x = (-b ± √‾(b2 - 4ac)) / 2a
Слайд 43 way(Full square extraction method)
solve the equation:
х2- 10х - 11 = 0
Select
a complete square on the left:
х2-10х - 11 = х2 -10 х +52 - 52 - 11 = (х 2 - 10 х +52)-36= (х-5)2 - 62
(х -5)2 - 62 =0
(x-5-6)(x-5+6)= 0
(x-11)(x+1)=0
х -11=0 или х + 1 = 0
х1 = 11 х2 = -1
Answer : 11; -1.
Слайд 5The meaning of this type of equation.
The considered solutions will help you
find different ways to solve quadratic equations and highlight rational ones among them. which can help save time when solving tests and assignments in mathematics on the exam.