1.When 90 minus the product of 6 and a number,the result is 36.find the number .
2.when the sun of 2 times a number and 6 is divided by 3, the result is 12.find the number.
3.20 minus the product of a number and 2 is equal to the square of 4 .find the number.
4.the sun of three consecutive number is 54 .find the three number.
5.the sun of three consecutive even number is 42. find the three number
6.the sun of three consecutive odd number is 81.find the three number
請用方程式，全部
Math(eng.)
2006-11-06 2:07 am
回答 (2)
2006-11-06 2:20 am
✔ 最佳答案
1.Let x be the number.
90 - 6x = 36
90 = 36 + 6x
54 = 6x
x = 9
2.
Let x be the number.
(2x + 6) / 3 = 12
2x + 6 = 36
2x = 30
x = 15
3.
Let x be the number.
20 - 2x = 4^2 ( Here, 4^2 means the square of 4 = 4*4)
20 - 2x = 16
20 = 16 + 2x
4 = 2x
x = 2
4.
Let x be the smallest number.
Then the middle number is (x + 1) and the largest number is (x + 2).
x + (x + 1) + (x + 2) = 54
3x + 3 = 54
3x = 51
x = 17
Therefore, the three numbers are 17, 18, 19
5.
Let x be the smallest number.
Then the middle number is (x + 2) and the largest number is (x + 4).
x + (x + 2) + (x + 4) = 42
3x + 6 = 42
3x = 36
x = 12
Therefore, the three numbers are 12, 14, 16.
6.
Let x be the smallest number.
Then the middle number is (x + 2) and the largest number is (x + 4).
x + (x + 2) + (x + 4) = 81
3x + 6 = 81
3x = 75
x = 25
Therefore, the three numbers are 25, 27, 29.
2006-11-06 2:43 am
1.Let x be the number.
(x+6)+36 = 90
x+6 = 54
x = 48
2.Let x be the number.
2x+ 6/3 = 12
2x+ 2 = 12
2x = 10
x = 5
3.Let x be the number.
4(4)+(x+2) =20
16+(x+2) = 20
x+2 = 4
x = 2
4.Let x be the smallest number.
x+ (x+1)+(x+2) = 54
3x +3 = 54
3x = 51
x =17
The three numbers are 17, 18 ,19.
5.Let x be the smallest even number.
x+ (x+2)+ (x+4) = 42
3x+ 6 = 42
3x = 36
x = 12
the three even numbers are 12, 14 ,16.
6.You can try it by yourself, just like question 4 & 5.
(x+6)+36 = 90
x+6 = 54
x = 48
2.Let x be the number.
2x+ 6/3 = 12
2x+ 2 = 12
2x = 10
x = 5
3.Let x be the number.
4(4)+(x+2) =20
16+(x+2) = 20
x+2 = 4
x = 2
4.Let x be the smallest number.
x+ (x+1)+(x+2) = 54
3x +3 = 54
3x = 51
x =17
The three numbers are 17, 18 ,19.
5.Let x be the smallest even number.
x+ (x+2)+ (x+4) = 42
3x+ 6 = 42
3x = 36
x = 12
the three even numbers are 12, 14 ,16.
6.You can try it by yourself, just like question 4 & 5.
參考: me
收錄日期: 2021-04-23 15:52:43
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061105000051KK04276