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:
7. r = -5
8. x = -1
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
Step-by-step explanation:
<u>Step 1: Define</u>
r + 2 - 8r = -3 - 8r
<u>Step 2: Solve for </u><em><u>r</u></em>
- Combine like terms: -7r + 2 = -3 - 8r
- Add 8r to both sides: r + 2 = -3
- Subtract 2 on both sides: r = -5
<u>Step 3: Check</u>
<em>Plug in r into the original equation to verify it's a solution.</em>
- Substitute in <em>r</em>: -5 + 2 - 8(-5) = -3 - 8(-5)
- Multiply: -5 + 2 + 40 = -3 + 40
- Add: -3 + 40 = -3 + 40
- Add: 37 = 37
Here we see that 37 does indeed equal 37.
∴ r = -5 is a solution of the equation.
<u>Step 4: Define equation</u>
-4x = x + 5
<u>Step 5: Solve for </u><em><u>x</u></em>
- Subtract <em>x</em> on both sides: -5x = 5
- Divide -5 on both sides: x = -1
<u>Step 6: Check</u>
<em>Plug in x into the original equation to verify it's a solution.</em>
- Substitute in <em>x</em>: -4(-1) = -1 + 5
- Multiply: 4 = -1 + 5
- Add: 4 = 4
Here we see that 4 does indeed equal 4.
∴ x = -1 is a solution of the equation.
Answer:
Gianna makes $18 per hour.
Step-by-step explanation:
Given Gianna makes 90$ for 5 hours. That means she should make $ = 18$ every hour.
Therefore we have:
a.
HOURS DOLLARS
1 18
2 36
3 54
4 72
5 90
6 108
7 126
b.
For the tabular column mark Hours on the x - axis and Dollars on the Y - axis. It can be plotted from the above table easily.
c.
If Gianna works for 8 hours she would have made 8 X 18 = 144$.
So, she will earn 144$ in 8 hours.
d.
To make 60$ she would have to work hours = 3.33 hours.
Answer:
Step-by-step explanation:
Given:
(-3, 3.6);
(5, 2)
Required:
Rate of change
SOLUTION:
Rate of change for the function is given as .
Let,
Rate of change =
Answer:
E
Step-by-step explanation:
If you add 22 onto the sum of all the points and divide by the amount of games (6), you get 12.