+0  
 
+11
1012
2
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x + y + z = 11

0.70x + 0.55y + 0.50z = 6.70

x = 3z

 Oct 23, 2015

Best Answer 

 #1
avatar+26396 
+30

x + y + z = 11

0.70x + 0.55y + 0.50z = 6.70

x = 3z

 

(1)x+y+z=11(2)0.70x+0.55y+0.50z=6.70x=3z:(1)3z+y+z=11(2)0.70(3z)+0.55y+0.50z=6.70(1)y+4z=11(2)2.1z+0.55y+0.50z=6.70(1)y+4z=11(2)0.55y+2.60z=6.70(1)y=114z(2)0.55y+2.60z=6.700.55(114z)+2.60z=6.700.55110.554z+2.60z=6.706.052.20z+2.60z=6.706.05+0.40z=6.700.40z=6.706.050.40z=0.65z=0.650.40z=1.625(1)y=114zy=1141.625y=116.5y=4.5x=3zx=31.625x=4.875

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 Oct 23, 2015
 #1
avatar+26396 
+30
Best Answer

x + y + z = 11

0.70x + 0.55y + 0.50z = 6.70

x = 3z

 

(1)x+y+z=11(2)0.70x+0.55y+0.50z=6.70x=3z:(1)3z+y+z=11(2)0.70(3z)+0.55y+0.50z=6.70(1)y+4z=11(2)2.1z+0.55y+0.50z=6.70(1)y+4z=11(2)0.55y+2.60z=6.70(1)y=114z(2)0.55y+2.60z=6.700.55(114z)+2.60z=6.700.55110.554z+2.60z=6.706.052.20z+2.60z=6.706.05+0.40z=6.700.40z=6.706.050.40z=0.65z=0.650.40z=1.625(1)y=114zy=1141.625y=116.5y=4.5x=3zx=31.625x=4.875

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heureka Oct 23, 2015
 #2
avatar
+5

x + y + z = 11

0.70x + 0.55y + 0.50z = 6.70

x = 3z

 

Solve the following system:
{y+4 z = 11 |     (equation 1)
0.55 y+2.6 z = 6.7 |     (equation 2)
Subtract 0.65 × (equation 1) from equation 2:
{4 z+y = 11 |     (equation 1)
0 z-0.1 y = -0.45 |     (equation 2)
Divide equation 2 by -1.:
{4 z+y = 11 |     (equation 1)
0 z+0.1 y = 0.45 |     (equation 2)
Divide equation 2 by 0.1:
{4 z+y = 11 |     (equation 1)
0. z+y = 4.5 |     (equation 2)
Subtract equation 2 from equation 1:
{4 z+0 y = 6.5 |     (equation 1)
0 z+y = 4.5 |     (equation 2)
Divide equation 1 by 4:
{z+0 y = 1.625 |     (equation 1)
0 z+y = 4.5 |     (equation 2)
Collect results:
Answer: | 
| {z = 1.625
y = 4.5

x=1.625 X 3=4.875

 Oct 23, 2015

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