✔ 最佳答案
1) let x,x+1,x+2 be the three value
x+(x+1)+(x+2)=48
3x+3=48
3x=45
x=15
so三個連續數is12,16and17.
2)let them be x,x+1
x+(x+1)=86
2x+1=86
2x=85
x=42.5
so果2個連續數係42.5,43.5
3)let the width of the rectangle be x,the length is 3x
2(x+3x)=24
4x=12
x=3
the width is 3, the length 3(3)=9
the area,
3‧9=27cm2
4)let 瑪莉be m,彼得be p,比堤be b.
1/2m = p
b = 3p
b = 3 x 1/2m
b = 3/2m
m+1/2m+3/2m = 120
m+4/2m = 120
3m = 120
m = 40
so 瑪麗hv 40 pieces,彼得hv 1/2(40) = 20 pieces and 比堤hv 3(20)=60pieces.
5)let y be the no. of turtles he bought
250-45-16y = 45
205-16y = 45
205-45 = 16y
160 = 16y
y=10
6a)let the width be x,the length be x+2
x+(x+2) = 36
2x = 34
x = 17
the area,
17‧(17+2) = 323cm2
6b)let the width be x
2(2+x) = 36
4+2x = 36
2x = 32
x = 16
the area,
2‧16 = 32cm2
2007-07-24 19:44:32 補充:
一次過,好辛苦呀!!=D
2007-07-24 19:46:41 補充:
對不起,第2題睇唔到係雙數,再做過2) let them be x,x 2x (x 2)=862x 2=862x=84x=42so果2個連續數係42,44