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Lana71 [14]
2 years ago
11

Two mechanics worked on a car. The first mechanic worked for

Mathematics
2 answers:
ivann1987 [24]2 years ago
5 0
20x + 15y = 2000
x + y = 115
55+60=115

20 (55) + 15 (60)=2000
1100+900=2000
2000=2000
Ira Lisetskai [31]2 years ago
4 0

x=price per hour for first mechanic

y=price per hour for second mechanic


20x+15y=2000

x+y=115

solve

divide first equation by 5

4x+3y=400


multiply second equation by -3 and add to second


4x+3y=400
<u>-3x-3y=-345 +</u>
1x+0y=55

x=55


x+y=115

55+y=115

minus 55

y=60


first mechanic rage is $55 per hour

second mechanic is $60 per hour


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f(x) = 4x^2+2x+6f(x)=4x 2 +2x+6f, left parenthesis, x, right parenthesis, equals, 4, x, squared, plus, 2, x, plus, 6 What is the
vladimir2022 [97]

<u>Given</u>:

The given function is f(x)=4x^2+2x+6

We need to determine the value of the discriminant f and also to determine the distinct real number zeros of f.

<u>Discriminant</u>:

The discriminant can be determined using the formula,

\Delta = b^2-4ac

Now, we shall determine the discriminant of the function f(x)=4x^2+2x+6

Substituting the values in the formula, we have;

\Delta=(2)^2-4(4)(6)

\Delta=4-96

\Delta=-92

Thus, the value of the discriminant of f is -92.

<u>Distinct roots:</u>

The distinct zeros of the function f can be determined by

(1) If \Delta>0, then the function has 2 real roots.

(2) If \Delta=0, then the function has 2 real roots ( or one repeated root).

(3) If \Delta, then the function has 2 imaginary roots (or no real roots).

Since, the discriminant is \Delta=-92 \ < \ 0 , then the function has no real roots  or 2 imaginary roots.

Thus, the function has 2 imaginary roots.

4 0
3 years ago
When 0.5(20x – 50y + 36) – 0.25(–100x + 40y – 12) is simplified, what is the resulting expression?
stiks02 [169]

Answer:

<h2>35x - 35y + 21</h2>

solution,

0.5(20x - 50y + 36) - 0.25( - 100x + 40y - 12) \\  = 10x - 25y + 18  + 25x - 10y + 3 \\

Combine the like terms:

= 10x + 25x - 25y - 10y + 18 + 3 \\

Simplify:

35x - 35y + 21

Hope this helps...

Good luck on your assignment...

6 0
3 years ago
Help for
Fed [463]
3 x 5 x 8 =15 x 8 = 120
5 0
3 years ago
This is due today I don’t get it.
erik [133]

Answer:

1. A, C, and D are on the line.

1st graph:

1. The slope is 2/3.

2. The y-intercept is (0, -1)

3. The equation is y = 2/3x - 1

2nd graph:

1. The slope is 4.

2. The y-intercept is (0, -3)

3. The equation is y = 4x - 3

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
A research company desires to know the mean consumption of meat per week among people over age 40. A sample of 610 people over a
Papessa [141]

Answer: (3.0,\ 3.2)

Step-by-step explanation:

Confidence interval for population mean is given by :-

\overline{x}\pm z_{\alpha/2}\dfrac{\sigma}{\sqrt{n}}  (1)

, where \overline{x} = Sample mean

z_{\alpha/2}= Critical z-value

\sigma = Population standard deviation.

n= Sample size.

As per given , we have

n= 610

\sigma=1.1

\overline{x}=3.1

Significance level for 85% confidence : \alpha=1-0.85=0.15

By z-table critical two tailed z-value : z_{\alpha/2}=z_{0.075}=1.44

Put all values in (1) , we get

3.1\pm 1.44\dfrac{1.1}{\sqrt{610}}

3.1\pm 1.44\dfrac{1.1}{24.698}

3.1\pm 0.064

=(3.1-0.064,\ 3.1+0.064)=(3.036,\ 3.164)\approx(3.0,\ 3.2)

Hence, the 85% confidence interval for the mean consumption of meat among people over age 40.  = (3.0,\ 3.2)

5 0
3 years ago
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