If the average of 4 and x is equal to the average of 2, 8, and x, what is the value of x?
2007-10-13 16:52:35 · 9 answers · asked by Lizzie 1 in Science & Mathematics ➔ Mathematics
(4+x)/2 = (2+8+x)/3
cross multiply
3(4+x) = 2 ( 10 + x)
12 + 3x = 20 + 2x
x = 8
2007-10-13 17:10:04 · answer #1 · answered by Anonymous · 0⤊ 0⤋
(4 + x) / 2 = (2 + 8 + x) / 3
3(4 + x) = 2(10 + x)
12 + 3x = 20 + 2x
x = 8
Answer: x = 8
Proof:
(4 + 8) / 2 = (2 + 8 + 8) / 3
12 / 2 = 18 / 3
6 = 6
2007-10-14 06:26:44 · answer #2 · answered by Jun Agruda 7 · 2⤊ 0⤋
(4+x)/2 = (2+8+x)/3
4/2 + x/2 = 2/3 + 8/3 + x/3
2 + x/2 = 10/3 + x/3
multiply everything by 6 to get rid of the fractions
6*2 + 6x/2 = 60/3 + 6x/3
12 + 3x = 20 + 2x
3x - 2x = 20 -12
x = 8
2007-10-13 23:57:21 · answer #3 · answered by Bill F 6 · 0⤊ 0⤋
(x + 4)/2 = (2 + 8 + x)/3
3x + 12 = 20 + 2x
x = 8
Check: ( 8 + 4)/2 = 6 = (2 + 8 + 8 )/3
2007-10-13 23:58:45 · answer #4 · answered by LucaPacioli1492 7 · 0⤊ 0⤋
(4+x)/2 = (2+8+x)/3
3(4+x)=2(10+x)
12 + 3x = 20 + 2x
x = 8
2007-10-13 23:56:52 · answer #5 · answered by norman 7 · 1⤊ 0⤋
(4+x)/2=(2+8+x)/3
2+0.5x=(10+x)/3
6+1.5x=10+x
0.5x=4
x=8
2007-10-14 00:06:08 · answer #6 · answered by sifonblue 1 · 0⤊ 0⤋
(4+x)/2=(2+8+x)/3
3(4+x)=2(2+8+x)
12+3x=4+16+2x
12+3x=20+2x
3x-2x=20-12
x=8
2007-10-13 23:59:24 · answer #7 · answered by bo1401@sbcglobal.net 2 · 0⤊ 0⤋
[09]
According to the problem
2(4+x)=2+8+x
8+2x=10+x
2x-x=10-8
x=2
2007-10-13 23:56:39 · answer #8 · answered by alpha 7 · 0⤊ 2⤋
((4+x)/2)=((2+8+x)/2)
6*((4+2)/2)=((10+x)/3)*6
3(4+x)=(10+x)2
(12+3x)-2x=(20+2x)-2x
(12+x) -12=20-12
x=8
2007-10-14 00:06:18 · answer #9 · answered by dantrc724 4 · 0⤊ 0⤋