(1)
if the two adjacent sides of a square measure x cm and (2x-3) cm respectively, find the perimeter of the square.
(2)
4 乘(3m ÷5) -2m-8=0
(3)
(8y-9)+(15-2y)=6-18
(4)
Amy had $100.She used part of her money to buy 7 ceramic cats,in which 3 of them are more expensive than the rest by $7 left ,how much do the two types of ceramic cat cost?
Please show the step
form2maths(快入)
2007-08-17 9:40 pm
回答 (2)
2007-08-17 9:59 pm
✔ 最佳答案
1) [ x + ( 2 x - 3 ) ] x 2= ( 3 x - 3 ) x 2
= 6 x - 6 cm
2) 4 x ( 3 m ÷ 5 ) - 2 m - 8 = 0
( 12 m ÷ 5 ) - 2 m = 8
12 m ÷ 5 = 8 + 2 m
12 m = 40 + 10 m
2 m = 40
m = 20
3) ( 8 y - 9 ) + ( 15 - 2 y ) = 6 - 18
8 y - 9 + 15 - 2 y = - 12
6 y + 6 = - 12
6 y = - 18
y = - 3
4) Let x be the cost of more expensive cat,
3 x + ( x - 7 ) ( 7 - 3 ) = 100
3 x + 7 x - 49 - 3 x + 21 = 100
7 x - 28 = 100
7 x = 128
x= 128/7
2007-08-17 10:00 pm
1)
as sides of squarr are equal, i.e. x = 2x-3
x = 3
Perimeter of square = 4*3
= 12cm
2)
4*(3m/5) - 2m - 8 = 0
12m/5 - 2m - 8 = 0
12m - 10m - 40 = 0
2m = 40
m = 20
3)
(8y - 9) + (15 - 2y) = 6 - 18
6y -9 + 15 = -12
6y = -18
y = -3
4)
Let x be the cost of the cheaper cat
Total cost spend = 4x + 3(x+7)
= 7x + 21
If the cheaper cat cost $ 11, total cost spend = $98
as sides of squarr are equal, i.e. x = 2x-3
x = 3
Perimeter of square = 4*3
= 12cm
2)
4*(3m/5) - 2m - 8 = 0
12m/5 - 2m - 8 = 0
12m - 10m - 40 = 0
2m = 40
m = 20
3)
(8y - 9) + (15 - 2y) = 6 - 18
6y -9 + 15 = -12
6y = -18
y = -3
4)
Let x be the cost of the cheaper cat
Total cost spend = 4x + 3(x+7)
= 7x + 21
If the cheaper cat cost $ 11, total cost spend = $98
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