Two equations two unknowns X / 3.51 + Y / 2.78 = 0.62 X / (x + y) = 0.3 every step in the process of solving this equation is written out There is a very simple step. I just can't remember it,

Two equations two unknowns X / 3.51 + Y / 2.78 = 0.62 X / (x + y) = 0.3 every step in the process of solving this equation is written out There is a very simple step. I just can't remember it,

The reduced equation is 0.62x = 0.3x + 0.3y
That is, 3.1 x = 3 y
Substituting 2.78x + 3.15y = 2.92734
(3 / 3.1 * 2.78 + 3.15) * y = 2.92734
y=2.92734/5.81129=0.503733=0.5

8 * (unknown - 3 / 4) = 5 / 4
There must be a process now, ha ha

8 * (x-3 / 4) = 5 / 4
x-3/4=5/32
x=29/32

Find the unknown x 4 / 5 x = 1 / 2 x: 3.2 = 4 7 / 7 x = 2 / 5 x 6 / 9

1. 4X / 5 = 1 / 2, x = 1 / 2 * 5 / 4 = 5 / 8 (5 / 8)
2、x/3.2=4,x=4*3.2=12.8
3. X / 7 = 2 / 5, x = 2 / 5 * 7 = 14 / 5 = 2 + 4 / 5 (4 / 2 / 5)
4. 6 / x = 8 / 9, x = 6 * 9 / 8 = 27 / 4 = 6 + 3 / 4 (6 and 3 / 4)

. find the unknown x.0.35 + 0.9 of X + 2 = 3 of 8

0.35+x/0.9=3/8
7/20+18x/20=3/8

Find the unknown x satisfying the following formula
1/3（2x+1)^3-1/8=1

1/3（2x+1)^3 = 9/8
（2x+1)^3 = 27/8
(2x+1) = 3/2
x = 1/4

Find the unknown x satisfying
（2x-1)(2x+1)=8

(2x-1)(2x+1)=8
4x²-1=8
4x²-9=0
(2x-3)(2x+3)=0
2x-3 = 0 or 2x + 3 = 0
X = 3 / 2 or x = - 3 / 2
If you don't understand this question, you can ask,
If you have other questions, you can go to "number one 365" to ask questions

Find the unknown x satisfying the following formula
Find the unknown x satisfying the following formula
(1) x²=49
(2) X & # 178; = 25 / 81

1: Plus or minus 7
2. Plus or minus 9 / 5
In fact, it's very simple to solve this kind of problem. As long as you think of a number multiplied by itself, the answer is that number is positive and negative. Remember, it's two
For example, in question 49, the answer must be plus or minus 7

Why is the letter X most widely used for unknowns?

Many physical quantities or units are expressed by the first letter of English. If you use those letters, it's easy to confuse. There are few English words beginning with X, so you don't have to worry about letter collision at any time

The first unknown is x, the second is y, and what about the third?

z

Solve the equation 150% X (multiply sign) x (unknown number) X90% - 10 = 125

1.5*0.9x＝125＋10
1.35x＝135
x＝100