How to solve the equation 85-x = 58 + X,

How to solve the equation 85-x = 58 + X,

transposition
x+x=85-58
2x=27
2x÷2=27÷2
x=13.5

99 + 3 / 4 (three quarters) + 199 + 3 / 4 + 2999 + 3 / 4 + 39999 + 3 / 4 + 1
Simple calculation

99 + 3 / 4 (three quarters) + 199 + 3 / 4 + 2999 + 3 / 4 + 39999 + 3 / 4 + 1
=99 + 199 + 2999 + 39999 + three quarters X4 + 1
=100-1+200-1+3000-1+40000-1+4
=100+200+3000+40000
=43300

Small + learn + number + learn = interesting questions

7+5+9+5=26

If the unit price of a commodity is 180 yuan after 10% price reduction, its unit price before price reduction is 180 yuan______ Yuan

According to the equation: X-10% x = 180, the solution is x = 200

Let y = f (x) be defined as R +, and f (XY) = f (x) + (y), f (8) = 3, then f (2) =?

f（8）=f（2）+f(4)=f(2)+f(2)+f(2)=3
f(2)=1

I don't understand
Let y = x ^ 2 + BX + C (B, C ∈ R), and a = {XIX = x ^ 2 + BX + C}, B = {XIX = (x ^ 2 + BX + C) ^ 2 + B (x ^ 2 + BX + C) + C}. It is proved that if a is a set with only one element, then a = B
Let a = {{a}, then the equation x ^ 2 + BX + BX + C-X = 0 has two equal real roots a, and then x ^ 2 + BX + BX + C-X is x ^ 2 + BX + C-X = (X-2 + BX + BX + C) equation x ^ 2 + BX + BX + c-x-x = x, there are two equal real roots a, so x ^ 2 + BX + bx-2 + bx-2 + BX + BX + bx-x + BX + bx-x + C-C-X + C-X + BX + BX + BX + BX + BX + BX + BX + BX + BX + BX ^ 2 + (x-a) ^ 2 [(x-a) ^ 2 [(x-a (x-a) [(x-x-x-a) [(x-x-a + 2 [(x-a + (x-a + 1) [(= {a} = a
I didn't understand from then on. I just graduated from junior high school
Struggling years - Assistant Level 3
But can you tell me the way to do this

In fact, there is more than one way to solve this problem
I feel that the answer is not very simple, we might as well explain it in this way;
Let a be a set with only one element, then x ^ 2 + BX + C = x, and there is only one solution. We can replace all x ^ 2 + BX + C in B set with 'x'. Then the condition x = (x ^ 2 + BX + C) ^ 2 + B (x ^ 2 + BX + C) + C in B set becomes x = x ^ 2 + BX + C. according to a set, he has only one solution, so obviously a = B
What you need to do when you see a question is to analyze the meaning of the question, find out useful conditions repeatedly, and then connect with the question you ask according to these things. Then answer

The original price of a computer is 8000 yuan. First, the price is increased by 3 / 10 and then reduced by 3 / 10. What's the current price of this computer?

After the price increase, the price is 8000 + 8000 * 3 / 10 = 10400
After the price reduction, it is 10400-10400 * 3 / 10 = 7380

The absolute value of the square root of 1-2 + the square root of 2 - the absolute value of the square root of 3 + the absolute value of the square root of 2 - 1 is equal to
|1 - √ 2 | + | √ 2 - √ 3 | + | √ 2-1 | = what

It's simple. Two is bigger than one
3 is bigger than 2,
And because absolute numbers are positive
therefore
Original formula = √ 2-1 + √ 3 - √ 2 + √ 2-1 = √ 2 + √ 3-2

The third times the 1999 power of 2, and then subtract the 2000 power of 2
Third, if the rational numbers a, B and C satisfy the following conditions: the absolute value of a in a + the absolute value of B in B + the absolute value of C in C = 1, then the absolute value of ABC in ABC=
The fourth known algebraic formula m square + M-1 = 0, then the algebraic formula m cube + 2m square + 2003 = ()
Second, there are countless beads ~ they are red (2) yellow (3) green (4)! So, what color is 256.

13 * 2 ^ 1999-2 ^ 2000 = 2 ^ 1999 (13-2) = 11 * 2 ^ 1999 represents the absolute value / A + / B + / C = 1, so ABC assumes that a = 1, B = 1, C = - 2 (it doesn't matter, it will be deleted anyway) / ABC = 2 / - 2 = - 1m ^ 2 + M-1 = 0, so m ^ 2 + M = 1, so m ^ 3 + m ^ 2 = m, so m ^ 3 + 2m ^ 2 + 2003 = m + m ^ 2 + 2003, because m ^ 2 + M = 1

A commodity is priced at 20% profit and sold at a 20% discount during the festival. After a loss of 80 yuan, how much is the cost of this commodity?

Let the cost be x yuan
（20%+1）*x*80%=x-80
0.04x=80
X = 2000 yuan
Answer