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4x + y + 3z = 34 4x + 3z = 21 What is the value of y?
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23 Jun 2018, 11:47
23 Jun 2018, 11:47
Expert Reply
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Question Stats:
98% (00:18) correct
2% (01:19) wrong based on 50 sessions
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Re: 4x + y + 3z = 34 4x + 3z = 21 What is the value of y?
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16 Jul 2018, 18:55
16 Jul 2018, 18:55
Expert Reply
Explanation
This question contains only two equations, but three variables. To isolate y, both x and z must be eliminated. Notice that the coefficients of x and z are the same in both equations. Subtract the second equation from the first to eliminate x and z.
\(4x + y + 3z = 34\)
\(-(4x + 3z = 21)\)
\(y = 13\)
This question contains only two equations, but three variables. To isolate y, both x and z must be eliminated. Notice that the coefficients of x and z are the same in both equations. Subtract the second equation from the first to eliminate x and z.
\(4x + y + 3z = 34\)
\(-(4x + 3z = 21)\)
\(y = 13\)
Re: 4x + y + 3z = 34 4x + 3z = 21 What is the value of y?
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18 Jul 2018, 17:57
18 Jul 2018, 17:57
1
sandy wrote:
This is super simple if you look at the equations closely and rearange them to look like this:
\(4x + 3z + y = 34\)
\(4x + 3z = 21\)
Notice how \(4x + 3z\) already equals 21? Well plug that in:
\(21 + y = 34\)
\(y = 13\)
The answer is \(y = 13\)
