There is a two-digit number, the number on the tenth digit is 2 less than the number on the fourth digit, and the product of the number on the tenth digit and the number on the fourth digit is exactly equal to this two-digit number. Find this two-digit number.

Solution: If the single digit is X, then the ten digits are X-2 x (X-2) 3 =10 (X-2)+X.

3 a？ 2-17x+20 = 0 (3x-5) (x-4) = 0x = 5/3 (truncated) or x=4.

Then these two digits are 24.

On a rectangular cultivated land with a length of 32m and a width of 20m, three roads with the same width were built, and the cultivated land was divided into six experimental fields with different sizes, so that the experimental field area was 570m2. What should be the width of the road?

Solution: Let the width be xm, 640-(20 * 2 * x+32 * x)+2x = 570.

x？ -36x+35=0 (X- 1)(X-35)=0

X= 1 or 35 (irrelevant, omitted) x= 1.

There are two consecutive integers whose sum of squares is 25. Find these two numbers.

Solution: Let these two numbers be a and a+ 1 respectively. According to the meaning of the question, set the equation: a? +(a+ 1)？ =25

Finishing: a? +a- 12=0 solution: a 1=3 a2=-4.

When a=3, the two numbers are 3 and 4 respectively. When a=-4, the two numbers are -3 and -4 respectively.