If the rank of a matrix is greater than or equal to 2, then at least two lines in the matrix are out of proportion. How can we prove this conclusion?

If the rank of a matrix is greater than or equal to 2, then at least two lines in the matrix are out of proportion. How can we prove this conclusion?

There are some in the textbook. Turn over the books
The rank of matrix A is greater than or equal to 2
At least two row vectors of matrix A are not linearly related
At least two lines in matrix A are out of proportion

To solve the equation (1) the difference between a certain number and 6 is 18. (2) a certain number is three seventh greater than it. (3) a certain number is six times smaller than it. (4) a certain number

1、x-6=18
x=24
2、x-（3x）/7=3/7
x=3/4
3、6x/6=10
x=10
4、.

How many inches is a foot?

One inch is equivalent to 2.54 cm;
One foot is equal to 12 inches, about 30.48 cm;
Yard (YD), one yard equals three feet, about 0.9144 meters

Xiao Ming finished reading a story book in three days. On the first day, he read 40% of the book. On the second day, he read the remaining 40%. On the third day, he read 12 more pages than on the second day. How many pages are there in this book?

Suppose this book has x pages, 40% x + (x-40% x) × 40% + (x-40% x) × 40% + 12 = x & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 0.4x + 0.24x0.24x + 12 = x

-a3+2b3-3ab+2=-______ =2-a3-______ ．

The original formula = - (a3-2b3 + 3ab-2) = 2-a3-3ab + 2b3

The car and truck set out from two places at the same time and went in opposite directions. After 1.3 hours, they were still 168 kilometers apart. After 2.5 hours, they met on the way
How many kilometers are the two places apart

Solution: set the distance between the two places x kilometers
x=168÷（2.5-1.3）x2.5
x=350

Given the side lengths 1 and 2 of a triangle, the third side length is the root of the square of 0.09y-0.21y + 0.1 = 0, and the perimeter of the triangle is obtained

According to 0.09y squared-0.21y + 0.1 = 0
a=0.09,b=-0.21,c=0.1
According to the root formula:
Y1 = - (B + (bsquare-4ac) square root) / 2A = 5 / 3
Y2 = - (B + (b square + 4ac) square root) / 2A = 2 / 3
If the length of the third side is 2 / 3, due to 1 + 2 / 3

A car goes from city a to city B in four fifths of an hour, three tenths of the whole journey. How many parts of the road can I travel in two hours?

15 out of 20

The letter A is known to represent a rational number. Which is bigger, a or - a?

When a = 0, a = - A
When A0. So - a > a
When a > 0, - A-A

The maximum acceleration of a fighter on an aircraft carrier during takeoff is 4.5m/s2, the aircraft's takeoff speed should reach v = 60m / s, the deck length of the aircraft carrier is L = 289m, the aircraft takes off safely, and the carrier should sail at a certain speed, then the minimum speed is______ ．

Let the time of the aircraft moving on the aircraft carrier be t, then the displacement of the uniform motion of the aircraft carrier in time t is X1 = VT, the displacement of the aircraft passing through is x2 = VT + 12at2, and the displacement of the aircraft taking off is V0 = V + at