The difference between the two numbers a must be less than the sum of the two numbers b 0 minus any rational number is equal to the opposite of the number

The difference between the two numbers a must be less than the sum of the two numbers b 0 minus any rational number is equal to the opposite of the number

A must be wrong. When the number is negative, it's wrong
B yes

Any rational number (except zero) has opposite number. Is that right?

Zero also has the opposite number, its opposite number is itself, so if this question also brings zero, it is completely correct!

1) One day, Xiao Fang and Xiao Gang solved a system of linear equations of two variables at the same time
ax+by=16… ①
bx+ay=1…… ② Xiao Fang copied equation (1) wrong and got the solution as follows:
x=-1
Y = 3; Xiao Gang copied equation ② wrong and got the solution as follows:
x=3
Y = 2, what is the solution of the original system of equations?
2) Known equations:
2x+5y=-6
mx-ny=-4
And equations
3x-5y=16
The solution of NX + my = - 8 is the same, find the value of the square of (2m + n)

Substituting x = - 1, y = 3 into (2) - B + 3A = 1
Substituting x = 3, y = 2 into (1) 3A + 2B = 16
a=2,b=5
2x+5y=16 5x+2y=1
y=26/7 x=-9/7
（2）2x+5y=-6 3x-5y=16
x=2 y=-2
2m+2n=-4 2n-2m=-8
m=1 n=-3

Two mathematics problems in grade one of junior high school
The original profit margin on sales of a commodity was 47%, but now the purchase price has increased by 5%, and the selling price has not changed, so the profit margin on sales of the commodity has changed to?
How much higher will the water surface increase when a rectangular iron block with a length of 5cm, a width of 3cm and a height of 3cm is immersed in a cylindrical glass with a radius of 4cm (containing water)
Please solve the equation, thank you!
Column equation ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!!!!!!!!!!!!!!

1. The price is set to Changshu A and the purchase price is set to X
The original profit margin is 47% = (A-X) / A
The solution is x = 0.53a
When the purchase price increases by 5%, the profit margin = [a - (1 + 5%) x] / A
The profit margin is 44.35%
2. The volume of water surface rising is equal to the volume of rectangular iron block, where the volume formula of water in the cylinder is v = s * H
V iron = 5 * 3 * 3 = 45 cm & # 179;
V water = V iron = s section * H (s is the section area of the cylinder, h is the height of water rising)
45=πr²*h
The solution is h ≈ 0.89 ≈ 0.9
So the water surface is 0.9CM higher

3/4X=17.5+5x%

3/4X=17.5+5x%
0.75X=17.5+0.05X
0.75X-0.05X=17.5
0.7X=17.5
X=17.5÷0.7
X=25

Given a function y = (M + 2) x + mm-m-4 image through the point (0,2), then the value of M is? Ask you fast!
Write the process!

The image of linear function y = (M + 2) x + mm-m-4 passes through the point (0,2)
When x = 0, y = 2
2=m^2-m-4
m^2-m-6=0
(m-3)(m+2)=0
M = 3 or - 2
m+2≠0
So m = 3

2008+200.8+20.08+2.008+199.2+19.92+1.992=

2008+200.8+20.08+2.008+199.2+19.92+1.992
=2008+200.8+199.2+20.08+19.92+2.008+1.992
=2008+400+40+4=2452

The perimeter of a right triangle is 36cm. The ratio of the length of its three sides is 5:4:3

36 ÷ (5 + 4 + 3) = 3 (CM) 3x5 = 15 (CM) 3x4 = 12 (CM) 3x3 = 9 (CM) because it is a right triangle, the two right angles are 12cm and 9cm, so the triangle area is: 12x9 ÷ 2 = 54 (square centimeter)

-52-19-37+24

-52-19-37+24
=-71-13
=-84

If the area of triangle DEF is known to be 1, what is the area of triangle ABC?
The area of ABC is 7, and the area of ABC is 2?

S (triangle ABC) = 4 * s (triangle DEF)
So the area is 4