math(easy~easy!!)hve 10 marks~!!^^要例式!!thank!!

1) Let X be the amount of money that joyce had:
Y be the the amount of money that michael had:
Then:
X = 30 + 6*3 + 12
X = 30 + 18 + 12
X = 60
Since: X = 3Y
So: Y = 60 / 3
= 20

2) Let X be the no. of apple that alan bought:
Y be the no. of orange that alan can bought:
Since the no. of orange = no. of apple
so X = Y
X * 2.5 + 2 = 3 * Y
When X = 4, then
4 * 2.5 + 2 = 3 * Y
12 = 3 * Y
Y =12/3
SO Y = 4
and thus the no. of apple and orange that alan can bought is consistance.

1)the amount of money foyce had was 3 times of michael`s.joyce spent $30 first and then bought 6 pens which cost $3 each ,she had $12 left.find the amount of money michael had.

Let Michael had $x,
Then Joyce had $3x

(3x-30)-(3*6)=12
(3x-30)=12+18
3x=30+30
x=60/3
x=20


2, In a supermarket, the price of an apple is $2.5, and an orange is $3. Alan got $2 left afterr buying some apples. However, he would need $2 more if he wanted to buy the same number of oranges.Find the number of apples he bought.

Let y the number of apples Alan bought.
2.5y+2=3A-2
2+2 = 3y-2.5y
4=0.5y
8=y
y=8
therefore the number of apples he bought = 8

我做過= =

1. Let y be the amount of money michael had,

3y = 30 + (6)(3) + 12
3y = 30 + 18 + 12
3y = 60
y = 20

Hence, Michael had $20.

2. Let y be the number of apples he bought,

2.5y + 2 = 3y - 2
0.5y = 4
y = 8

Hence, Alan bought 8 apples.

1) J = 3xM
J=12+6x3+30
=$60
M=60/3
=$20

2) Let x be the number of apples bought
y be the money alan got
2.5x+2=y
3x=y+2

3x=2.5x+2
0.5x=2
x=4
Therefore, number of apples bought is 4.