2007-02-04 06:02:27 · 9 answers · asked by freya 1 in Science & Mathematics ➔ Mathematics
To answer this question, keep in mind that the perimiter is twice the width plus twice the length. So, 70 = 2(4x-1) + 2(6x-4).
70 = 2(4x-1) + 2(6x-4) divide everything by 2
35 = 4x - 1 + 6x - 4 combine like terms
35 = 10x - 5 add 5 to both sides
40 = 10x divide both sides by 10
4 = x you have solved for x
Now, simply substitute 4 for x in the equation for the length.
length = 6x - 4 substitute 4 for x
length = 6(4) - 4 multiply
length = 24 - 4 subtract
length = 20 cm final answer
Hope this helps!
2007-02-04 06:21:37 · answer #1 · answered by Penya 4 · 0⤊ 0⤋
(4x-1) *2 + (6x -4)*2 = 70 (that is 2 times width +2 times length = perimeter)
8x-2 +12x-8 =70
20x -10 =70
20x =80
x= 4
length = 6x-4 = 6*4 -4 = 20 cm
width = 4x-1 = 4*4 -1 = 15 cm
perimeter = 20 +20 + 15 +15 = 70 whic checks the given conditions.
2007-02-04 06:14:29 · answer #2 · answered by bignose68 4 · 0⤊ 0⤋
2[(4x - a million) + (6x - 4)] = 70 (4x - a million) + (6x - 4) = 70/2 4x - a million + 6x - 4 = 35 4x + 6x = 35 + a million + 4 10x = 40 x = 40/10 x = 4 (4x - a million) cm = [4(4) - a million] cm = [sixteen - a million] cm = 15 cm ? the width is 15 cm.
2016-12-13 08:40:06 · answer #3 · answered by hume 4 · 0⤊ 0⤋
perimeter of a rectangle = width + length + width + length
so; (all unit in cm)
70 = (4x - 1) + (6x - 4) + (4x - 1) + (6x - 4)
70 = 2(4x - 1) + 2(6x - 4)
70 = (8x - 2) + (12x - 8)
70 = 8x + 12x + (-2) + (-8)
70 = 20x - 10
so;
20x = 70 +10
x = 80 / 20
x = 4 cm.......ans.
check:
width is (4x - 1)cm
width is (4(4) - 1)cm
w = 15cm....ans
length is (6x - 4)cm
length is (6(4) - 4)cm
l = 20 cm..............ans
70 = 15 + 15 + 20 + 20
70 = 70 .................both side is same so this value is right.
2007-02-11 17:14:53 · answer #4 · answered by Sir Jas 2 · 0⤊ 0⤋
the perimeter is the total of all the sides added up. that means that its 4x-1 +4x-1 +6x-4+6x-4
then you have to simplify it
20x-10
this equals the perimeter which is 70
so 20x-10=70
what you do to one side you do to the other so you can simplify it even more
20x-10+10=70+10
20x=80
divide 20x by 20 and you get x by itself divide 80 by x and you get what x equals
x=4
put x back into the length equation you get 6 times 40 -4
24-4 =20
The length equals 20
2007-02-11 17:44:19 · answer #5 · answered by Anonymous · 0⤊ 0⤋
First solve for x using the knowns:
p= 2*w +2*l
70= 2(4x-1)+ 2*(6x-4)
70=8x-2+12x-8
70= 20x-10
80= 20x
x=4
Now calculate the width by substituting for x:
w= 4x-1
w= 4(4)-1
w= 16-1
W= 15cm
2007-02-04 06:11:27 · answer #6 · answered by sciencewiz 4 · 0⤊ 0⤋
You already told us....6x-4
What you mean is solve for x I think.
The perimeter of a rectangle is 2L+2W=P
so 2(6x-4)+2(4x-1)=70
12x-8+8x-2=70
20x-10=70
20x=80
x=80/20
x=4
L=6x-4
L=6(4)-4
L=24-4
L=20
Length is 20cm
2007-02-11 11:08:16 · answer #7 · answered by Matt S 2 · 0⤊ 0⤋
2(4x-1)+2(6x-4)=70
8x-2+12x-8=70
20x-10=70
20x=80
x=4
6(4)-4
24-4=20
The length is 20 cm.
2007-02-04 07:41:09 · answer #8 · answered by Anonymous · 0⤊ 0⤋
p=70
p=2w+2l
70=2(4x-1)+2(6x-4)
70=8x-2+12x-8
80=20x
x=4
l=(6(4)-4)
l=24-4=20
2007-02-08 07:23:35 · answer #9 · answered by Michelle M 2 · 0⤊ 0⤋