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1)The sum of two consecutive integers is 85 .find the integer .
1)If 6 is subtracted from a number .the result is equal to one-third od the number .Find the number
3)John is 5 years older than his brother David .The sum of their ages is 35 .How old is David?
4)12(x-3)=7x-6
5)6y-1/2=2y-9
6)o.6y-0.3=0.5y
7)1/y-1/2y=1/10
8)Afather's age is 5 times of his son .If the sum of their ages is 48 .find the son 's age
回答 (2)
ans:
1.
let x&(x+1) be the integers.
x+(x+1)=85
2x=84
x=42
∴The integers are 42&43.
2.
let x be the number.
1
x-6=---(x)
3
3x-18=x
2x=18
x=9
∴the number is 9.
3.
let x years old be the age of david.
x+(x+5)=35
2x=30
x=15
∴david is 15 years old.
4.
12(x-3)=7x-6
12x-36=7x-6
5x=30
x=6
5.
1
6y- --- = 2y-9
2
12y-1 = 4y-18
8y=-17
17
y=- ----
8
6.
0.6y-0.3=0.5y
0.1y=0.3
y=3
7.
1 1 1
--- - ---- = ---
y 2y 10
10-5=y
y=5
8.
let x years old be the age of the son.
x+5x=48
6x=48
x=8
∴the son is 8 years old.
1)42,43
2)9
3)x+(x+5)=35
x=15
David is 15 year old
4) x=6
5)y= -8.5
6)y=0.1
7)y=5
8)x+5x= 48
x=8
參考: me
收錄日期: 2021-04-23 21:54:59
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