If x2 + 5x-990 = 0, then the value of X3 + 6x2-985x + 1012 is () A. 2000B. 2001C. 2002D. 2003

If x2 + 5x-990 = 0, then the value of X3 + 6x2-985x + 1012 is () A. 2000B. 2001C. 2002D. 2003

∵ x2 + 5x-990 = 0, ∵ x2 + 5x = 990, ∵ X3 + 6x2-985x + 1012, = x (x2 + 6x-985) + 1012, = x (x2 + 5x-990 + X + 5) + 1012, = x (x2 + 5x-990) + (x2 + 5x) + 1012, = 0 + 990 + 1012, = 2002

Solution equation: 5x - (20-x) X3 = 68

5x-60+3x=68
8x=128
x=16

To solve the fractional equation: x + 6 / 2x-3 = 3 / 1; 1-x2 = 1-x / 3; 1-x / 2 + 1 = 1 + X / X

x+6/2x-3=3/1
Jie: the original formula can be reduced to: (x + 6) * 1 = (2x-3) * 3
X+6=6X-9 5X=15 X=3
Test: when x = 3, 2x-3 is not equal to 0
So: the solution of the original fractional equation is x = 3
1-X/2＝1-X/3
The original formula can be reduced to: (1-x) * 3 = (1-x) * 2
3－3X＝2－2X
X＝1
Test: when x = 1, 1-x = 0, so the original fractional equation has no solution
1－X/2+1＝1＋X/X
The original equation can be reduced to: (1-x) * x = 3 * (1 + x)
X-x (quadratic) = 3 + 3x
X (second visit) + 2x = 3
X (second visit) + 2x + 1 = 2
(x + 1) second visit = 2
X + 1 = positive and negative root sign 2
X = positive and negative root sign 2-1
Test: when x = positive and negative root sign 2-1, X is not equal to 0
Therefore, x = positive and negative root sign 2-1 is the solution of the original fractional equation

X2 + X + 1 = 2 / (x2 + x) to solve fractional equation
Thank you

x2+x+1=2/(x2+x)
(X²+x)²+(x²+x)-2=0
(x²+x+2)(x²+x-1)=0
∴x²+x-1=0
x=(-1±√5)/2
x1=(1+√5)/2,x2=(-1-√5)/2

To solve the fractional equation: x2 + 5 of x plus 3 of x2-x = 7 of x2-1

Both sides of the equation are multiplied by X (x + 1) (x - 1) at the same time
5(x-1)+3(x+1)=7x
The solution is: x = 2
Test: X (x + 1) (x-1) = 6
So x = 2 is the solution of the original fractional equation

The solution equation: x2-5x-7 = 0

x2-5x-7=0
Formula method:
X = 1 / 2 (5 - radical [53])
X = 1 / 2 (5 + radical [53])

Solving the equation x2-5x + 2 = 0

x2-5x+2=0
x2-5x+25/4+2-25/4=0
x2-5x+25/4+2-25/4=0
(x-5/2)^2=17/4
x-5/2=±√17/4
x=5/2±1/2√17
x=1/2(5±√17)
If it helps you, please remember to adopt it_ Thank you

Solve the equation x2 + 5x + 4 = 0
emergency

(x+4)(x+1)=0
Ψ x + 4 = 0 or x + 1 = 0
x=-4 x=-1

0.4x plus 0.9 minus 0.03 0.05 plus 0.02x equals 2 x minus 5

If the denominator is changed into an integer, 4x / 5 + 0.9 - (5 + 2x) / 3 = (X-5) / 2
Go to both sides of denominator and multiply by 30:24x + 27-10 (5 + 2x) = 15 (X-5)
Remove brackets: 24x + 27-50-20x = 15x-75
Transfer: 24x-20x-15x = - 75 + 50-27
Merge congeners: - 11x = - 52
Divide both sides by - 11: x = 52 / 11

0.4x + 6.9-0.03 0.02x + 0.03 = 2 X-5

(0.4x+6.9)/0.5-(0.02x+0.03)/0.03=(x-5)/2
12(0.4x+6.9)-200(0.02x+0.03)=3(x-5)
4.8x+82.8-4x-6=3x-15
0.8x+76.8=3x-15
2.2x=91.8
x=459/11