Calculate (x + 1) (3x-2) - (3x + 1) (x-1)

Calculate (x + 1) (3x-2) - (3x + 1) (x-1)

(x+1)(3x-2)-(3x+1)(x-1)
=(3x+1)(x+1)-3(x+1)-(3x+1)(x-1)
=(3x+1)(x-1)+2(3x+1)-3(x+1)-(3x+1)(x-1)
=6x+2-3x-3
=3x-1

2 / 5x + 4 / 5 = 3x + 1 / 5

2/5x+4/5=3x+1/5
4/5-1/5 = 3x-2/5 x
3/5 = 15/5x-2/5x
3/5 = 13/5x
X = 3 / 5 divided by 13 / 5
x=3/5 * 5/13
x=3/13

81 = 9 & # 178; what is the logarithmic form? ㏒ one in twenty-seven, one in three after reduction___ N
.

81 = 9 & # 178; what is the logarithmic form
Is log [9] 81 = 2
㏒ one in twenty-seven, one in three
log 【 1/27】N =1/3
N= 【 1/27】^(1/3)=1/3
So n = 1 / 3

Mathematics in Grade 6, please answer in detail, thank you! (19:18:49:22)
There are two kinds of work, Zhang alone to complete a work to 10 days, alone to complete B work to 15 days; Li alone to complete a work to 8 days, alone to complete B work to 20 days. If each work can be two people cooperation, then, Zhang, Li together to complete the two work at least how many days

It takes X days for Zhang and Li to cooperate to complete the first task, and y days to complete the second task, sharing x + y days
(1 / 10 + 1 / 8) x = 1, x = 40 / 9, take x = 5
(1 / 15 + 1 / 20) y = 1, y = 60 / 7, y = 9
Shared 14 days

It is known that a = - 3x's Square - 2mx + 3x + 1, B = 2x's square + 2mx-1, and the value of 2A + B is independent of X, so the value of M is obtained

It should be 2A + 3B
=-6x²-4mx+6x+2+6x²+6mx-3
=(2m+6)x-1
Independent of X, the coefficient is 0
2m+6=0
m=-3

Let f (x) = ax + 1 / x + 2A be an increasing function in the interval (- 2, ∞), then the value range of a is

Why does the calculated value of a not exist? Classification discussion: 1) a = 0, f (x) = 1 / x, an inverse proportional function, does not satisfy that it is an increasing function in the interval (- 2, ∞), and is rounded off; 2) the function image of a & gt; 0, f (x) is a check function, and then moves up several units, which is about this: (a = 1) 3) a & lt; 0

How many square meters is 400 hectares

1 hectare = 100 square kilometers
therefore
400 ha = 400 km2

The square of x minus 17 plus 52 equals 0 to find X

X－17X＋52＝0 ﹙X－13﹚﹙X－4﹚＝0 X＝13 X＝4

If the tangent at a point m on the curve y = 15x5 is perpendicular to the straight line y = 3-x, then the equation of the tangent is______ ．

Let the point m (x0, Y0) ∵ tangent be perpendicular to the straight line y = 3-x ∥ the slope of the tangent be 1 ∥ the derivative of the curve at point m is y ′ = X04 = 1, that is, x0 = ± 1. When x0 = 1, Y0 = 15, the tangent equation is obtained by using the point oblique formula: 5x-5y-4 = 0; when x0 = - 1, Y0 = - 15, the tangent equation is obtained by using the point oblique formula: 5x-5y + 4 = 0. To sum up, the tangent equation is 5x-5y-4 = 0 or 5x-5y + 4 = 0 x-5y+4=0．

A simple method of 1 / 6 times 35 + 5 / 6 times 17

1 / 6 times 35 + 5 / 6 times 17
=1/6*5*7+5/6*17
=5/6*7+5/6*17
=5/6*(7+17)
=5/6*24
=20
Hope to help you!