The values of the variables are x = -2, y = 6 and z = -3
<h3>How to solve by elimination?</h3>
The system is given as:
4x + 2y - 2z = 10 (A)
2x + 8y + 4z = 32 (B)
30x + 12y - 4z = 24 (C)
The easiest variable to eliminate is z.
Combine A and B
2[4x + 2y - 2z = 10]
⇒
8x + 4y - 4z = 20
+ 2x + 8y + 4z = 32
⇒ 10x + 12y = 52
Combine B and C
2x + 8y + 4z = 32
30x + 12y - 4z = 24
⇒ 32x + 20y = 56
Divide through by 4
8x + 5y = 14
So, we have:
10x + 12y = 52
and
8x + 5y = 14
Multiply 10x + 12y = 52 by 8/10
8/10[10x + 12y = 52]
⇒ 8x + 9.6y = 41.6
Combine 8x + 9.6y = 41.6 and 8x + 5y = 14
8x + 9.6y = 41.6
- [8x + 5y = 14]
⇒ 4.6y = 27.6
Divide
y = 6
Substitute y = 6 in 8x + 5y = 14
8x + 5 * 6 = 14
8x + 30 = 14
Subtract 30
8x = -16
Divide
x = -2
Substitute y = 6 and x = -2 in (A)
4x + 2y - 2z = 10
4(-2) + 2(6) - 2z = 10
-8 + 12- 2z = 10
Evaluate the like terms
-2z = 6
Divide
z = -3
Hence. the values of the variables are x = -2, y = 6 and z = -3
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Answer:
=25 %
Step-by-step explanation:
Percent decrease equals (original minus new) / original * 100 %
Percent decrease = (85-64)/ 85 * 100%
= 21/85 * 100%
=.247058824 * 100%
=24.7058824%
To the nearest percent
=25 %
Answer:
48 minutes
Step-by-step explanation:
Given that:
Time taken by Janet = 3 hours
Janet's rate = 1/3 job / hour
Time taken by Garry = 2 hours
Garry's rate = 1/2
Rate of working together :
1/3 + 1/2 = (2 + 3) /6 = 5/6 job/hour
If Janet works for one hour before Garry joins ;
1/3 of the job has been done by Janet
1 - 1/3 = 2/3 of the job left
Hence to finish the job together, it will take :
Fraction of JOB left ÷ rate of working together
(2/3 ÷ 5/6)
= 2 /3 * 6/5
= 12 / 15
= 4 / 5 hours
To minutes
(4/5) * 60
= 240/5
= 48 minutes
Answer: i think its 75 srry if wrong
Step-by-step explanation:
Answer:
the decimal is 0.44 repeated