2 x + 6 x + 12 x + 20 x + 30 x + 42 x = 6 solution (process)

2 x + 6 x + 12 x + 20 x + 30 x + 42 x = 6 solution (process)

X/1*2+X/2*3+X/3*4+X/4*5+X/5*6+X/6*7=6
X(1-1/2)+X(1/2-1/3)+X(1/3-1/4)+X(1/4-1/5)+X(1/5-1/6)+X(1/6-1/7)=6
X(1-1/2+1/2-1/3+(1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7)=6
X(1-1/7)=6
X*6/7=6
X=6*7/6
X=7

8 = 7-2y, the linear equation of one variable

8=7-2y
Transfer: 2Y = 7-8
Merge similar items: 2Y = - 1
The coefficient is changed to 1: y = -- & # 189;

What points should we pay attention to when solving the equation of one variable and one degree? (8 points in total) give 30 points if the answer is correct

In order to avoid mistakes in solving the equation, we should pay attention to the following eight points: first, pay attention to the format of solving the equation. Every step of solving the equation must be an equation, so the format of "even equation" or "original solution =" is wrong

It is known that the two right sides of the right triangle ABC are a and B, and a and B are two of the equations X & # 178; - 7x + 10 = 0, then the circumscribed circle area of the right triangle ABC is

You can solve X1 = 2, X2 = 5, and then do it with the radius of the circumscribed circle

The length of three sides of a right triangle is an integer, and the length of one side is the root of the quadratic equation 2x2-23x + 11 = 0. Find the area of the right triangle

The integral root of the equation 2x ^ 2-23x + 11 = 0 is 11, so the length of one side of the right triangle is 11. If 11 is a right side of the right triangle, then a ^ 2 + 11 ^ 2 = B ^ 2, that is, (a + b) (a-b) = 121 = 1 * 121, so a + B = 121a-b = 1 gets a = 61, B = 60, then the area of the triangle is s = (1 / 2) * 11 * 60 = 330

Given that the lengths of two sides of a right triangle are exactly two of the equation x ^ 2-7x + 12 = 0, what is the length of the middle line on the writing side of the right triangle?

The solution is: X1 = 3, X2 = 4;
It can be a right angle or a hypotenuse
Then when C = 4, the length of the middle line on the write side is 4 / 2 = 2;
When a = 3, B = 4, C = √ (a ^ 2 + B ^ 2) = 5;
Then the length of the middle line on the writing edge is 5 / 2

Five out of eight minus thirty percent x is three out of twenty

Five out of eight minus thirty percent x equals three out of twenty
5 / 8-3 / 10x = 3 / 20 double 40
25-12x=6
12x=25-6
12x=19
x=19/12

Is the meaning of 0.5 (20% X-15) ok?

No, I can't
It should be: the difference between 20% of a certain number and half of 15

X / 3-3 / 5 = 4x, what is x equal to

Good
x/3-3/5=4x
4x-x/3=-3/5
11/3x=-3/5
x=-3/5 ÷11/3
x=-9/55
Comments
Perfect my answer

If the real number x satisfies the condition (x ^ 2 + 4x-5) ^ 2 + | x ^ 2-x-30 | equals 0, find √ (x + 1) ^ 2 - √ (x-1) ^ 2

The sum of two nonnegative terms = 0, two nonnegative terms = 0, + 4x-5 = 0 (x + 5) (x-1) = 0x = - 5 or x = 1 x & # 178; - X-30 = 0 (X-6) (x + 5) = 0x = 6 or x = - 5. If both terms are 0, then only x = - 5 √ (x + 1) &# 178; - √ (x-1) &# 178; = | x + 1 | - | X-1 | = | - 5 + 1 | - | 5-1 | =