All categories

3 years ago

Plz help me 75 points for the 2 questions!!!

Mathematics

1 answer:

liraira [26]3 years ago

3 0

Answer:

<u>The system of equations:</u>

2x + 7y = -11
3x + 5y = -22

Solve by elimination.

<u>Triple the first equation, double the second one, subtract the second from the first and solve for y:</u>

3(2x + 7y) - 2(3x + 5y) = 3(-11) - 2(-22)
6x + 21y - 6x - 10y = -33 + 44
11y = 11
y = 1

2x + 7*1 = -11
2x = -11 - 7
2x = -18
x = -9

<u>The solution is:</u>

x = -9, y = 1

<u>Simplifying in steps:</u>

8u - 29 > -3(3 - 4u)
8u - 29 > - 9 + 12u
12u - 8u < -29 + 9
4u < -20
u < -5

You might be interested in

Find the equation of the line that passes through the given point and has the given slope. (Use x as your variable.) (0, 9), m =

OleMash [197]

Answer:

y= 3x +9

Step-by-step explanation:

m= 3

The y-intercept of the line that passes through the given point (0,9) is

9 = 0(3) + b

b= 9

The equation of the line that passes through the given point (0,9) is

y =mx +b

y = 3x +9

8 0

3 years ago

A box with a square base and open top must have a volume of 97556 c m 3 cm3 . We wish to find the dimensions of the box that min

Kipish [7]

Answer:

S(x) = x² + 390224/x

Step-by-step explanation:

Volume of the open box = V = 97556 cm³

Material needed:

Let´s call x the side of the square base then the area of the base is

A(b) = x²

For the sides of the box, we have 4 sides each one with area of x*h

where h is the height of the box

The volume of the box V(b) = 97556 = x²*h then h = 97556/x²

S(x,h) = x² + 4*x*h*

The surface area of the box as function of x is:

S(x) = x² + 4*x*97556/x²

S(x) = x² + 390224/x

6 0

3 years ago

A sample of 14001400 computer chips revealed that 69i% of the chips fail in the first 10001000 hours of their use. The company's

puteri [66]

Answer:

No, there is not enough evidence at the 0.02 level to support the manager's claim.

Step-by-step explanation:

We are given that the company's promotional literature states that 71% of the chips fail in the first 1000 hours of their use. Also, a sample of 1400 computer chips revealed that 69% of the chips fail in the first 1000 hours of their use.

And the quality control manager wants to test the claim that the actual percentage that fail is different from the stated percentage, i.e;

Null Hypothesis, $H_0$ : p = 0.71 {means that the actual percentage that fail is same as the stated percentage}

Alternate Hypothesis, $H_1$ : p $\neq$ 0.71 {means that the actual percentage that fail is different from the stated percentage}

The test statistics we will use here is;

T.S. = $\frac{\hat p -p}{\sqrt{\frac{\hat p(1- \hat p)}{n} } }$ ~ N(0,1)

where, p = actual percentage of chip fail = 0.71

$\hat p$ = percentage of chip failed in a sample of 1400 chips = 0.69

n = sample size = 1400

So, Test statistics = $\frac{0.69 -0.71}{\sqrt{\frac{0.69(1- 0.69)}{1400} } }$

= -1.620

Now, at 0.02 significance level, the z table gives critical value of -2.3263 to 2.3263. Since our test statistics lie in the range of critical values which means it doesn't lie in the rejection region, so we have sufficient evidence to accept null hypothesis.

Therefore, we conclude that the actual percentage that fail is same as the stated percentage and the manager's claim is not supported.

7 0

3 years ago

If 12m=5n, then m/n=?

nignag [31]

Answer:

$\frac{m}{n}=\frac{5}{12}$