急!!!!!今日要做完!!!!maths 20 點

1.The sum of three consecutive numbers is 48.Find the numbers.

1.because:48/3=16
48=16+16+16
48=（16-1）+16+（16+1）
so:48=15+16+17

the numbers are:15,16,17

2.The sum of two consecutive even numbers is 86.Find the numbers.

2.because:86/2=43,43 isn't even numbers
86=43+43
86=（43-1）+（43+1）
so:86=42+44

the numbers are:42,44

3.The length of a rectabgle is 3 times its width,and the perimeter is 24 cm.Find the area of the rectangle.
3.24/4x3
=6x3
=18cm

hope i can help you

1) 8, 16 and 24
2) 38 and 48
3) 27 cm^2

1. 8&16&24

2. 38&48

3. 27cm

1. 8,16,24
2. 38,48
3. 27square cm

1. Let the smallest number is X, then x + x+1 + x+2 = 48
----> 3x + 3 = 48
-----> x = 15
therefore the numbers are 15, 16 & 17

2. Let the smaller number is y, then y + y + 2 = 86
-----> 2y + 2 = 86
-----> y = 42
therefore the numbers are 42 & 44

3. Let the width of rectangle is z, then length is 3z
------> (z+3z) * 2 = 24
------> 8z = 24
------> z = 3
therefore the width is 3 and the length is 3 * 3 = 9
hence the area is 3 * 9 = 27