Y=6x (1)
y=5x-7 (2)
Substitute y into (2)
(6x)=5x-7 -- subtract 5x from both sides
x=-7
Sub x into 1
y=6(-7)
y=-42
x=-7
y=-42
3(x)-5=x+5
3x=-5+5+x
3x=x
0=x
because 3x=x is basically would make each part into 0 which would end up the same.
Hey You!
16 - 20 / 16 * 100 = 25
The percentage increase from 16 to 20 is 25%. =)
Answer:
185/24
Step-by-step explanation:
Convert both to fractions with the same denominator first.
35/8= 105/24
10/3= 80/24
105/24+80/24
= 185/24
1 )
1st and 2nd equation (multiply 1st by -2 ):
-2x - 10 y + 8 z = 20
2 x - y + 5 z = -9
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- 11 y + 13 z = 11 / * ( -20 )
1st and 3rd:
- 2 x - 10 y + 8 z = 20
2 x - 10 y - 5 z = 0
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- 20 x + 3 z = 20 / * 11
----------------------------------
220 y - 260 z = -220
- 220 y + 33 z = 220
------------------------------
z = 0, y = -1, x = - 5
2 )
2 x - y + 5 = -4
- 2 x + 3 y - 5 = - 10
Substitution: y = 2 x + 9
- 2 x + 3(2 x + 9 ) = -5
4 x = - 32, x = -8, y = -7, z = 5
3 )
x + y + z = 11
1.5 x+3 y +1.5 z = 21
x = 2 y
------------------------
3 y + z = 11 / * (-2)
6 y + 1.5 z = 21
------------------------
- 6 y - 2 z = -22
6 y + 1.5 z = 21
------------------------
-0.5 z = -1, z = 2, y = 3, z = 6
Answer: the store used 6 pounds of peanuts, 3 pounds of almonds and 2 pounds of raisins.
