Предмет: Алгебра, автор: estrescova1

решите неполные уравнения:
-4x^2-4x=0
-5x^2-9x=0
-6x=0
1/5x^2-5=0
1/4x^2-1=0
2x^2+3x=0
4/5x^2-45=0
x^2+x=0
-4/3x^2+27=0
2(5x-7)(1+x)=0
25-x^2=0
18-x^2=14
4-36x^2=0
x^2+2=x+2
x^2+3=3-x
2x^2-14=0

Ответы

Автор ответа: zhenyaM2002
0
-4х² - 4х = 0
- 4х (х  + 1) = 0
произведение =0, если один из множителей = 0
-4х = 0
х₁ = 0
х + 1 = 0
х₂ = -1

5х²  - 9х  = 0
х(5х - 9) = 0
х₁= 0
5х - 9 = 0
5х = 9
х = 9/5
х ₂= 1,8

-6х = 0
х = 0

¹/₅ х² - 5 = 0
¹/₅ х²  = 5
х²  =  5 :  ¹/₅  =  5 * ⁵/₁ 
х² = 25
х₁ = √25
х₁ = 5
х₂ = -√25
х₂ = - 5

¹/₄ х² -  1 = 0
(¹/₂ х)²  - 1²  = 0
(0,5х  - 1)(0,5х + 1) = 0
0,5х  - 1 = 0
0,5 х = 1
х = 1/0,5
х₁ = 2
0,5х   + 1 = 0
0,5х = -1
х = - 1/0,5
х₂ = - 2

2х² + 3х = 0
х (2х + 3) =0
х₁ = 0
2х + 3 = 0
х₂ = - 1,5

⁴/₅ х² - 45 = 0
0,8х²  = 45
х²  = 45/0,8
х² = 56,25
х₁ = 7,5
х₂ = - 7,5

х² + х =0
х(х+1) =0
х₁ = 0
х + 1=0
х₂ = -1

2(5х -7)(1+х) = 0
5х - 7 =0
5х = 7
х = 7/5
х₁ = 1,4
1 + х = 0
х₂ = -1

25 - х² = 0
(5-х)(5+х) =0
5 - х = 0
-х = -5
х₁ = 5
5 +х = 0
х₂ = - 5

18  - х² = 14
18  - х² -14 = 0
4 - х²  = 0
2²  - х² = 0
(2 -х)(2+х) = 0
2 - х = 0
х₁ = 2
2 + х = 0
х₂ = -2

4 - 36х² = 0
2²  - (6х)² = 0
(2-6х)(2+6х)=0
2 - 6х = 0
- 6х = -2
6х = 2
х =2/6
х₁ = 1/3
2 + 6х =0
6х = -2
х₂ = - 1/3

х² + 3 = 3 - х
х²  + 3 - 3 +х = 0
х²  + х =0
х(х+1) =0
х₁=0
х+1=0
х₂ = -1

2х² - 14=0
2(х²  - 7) = 0     |÷2
х² - 7 =0
x² = 7
x₁ = √7
x₂ = - √7
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