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4 years ago

A sample that does not accurately represent the population is a _________.

Mathematics

1 answer:

Zinaida [17]4 years ago

6 0

The word "random' does not describe the sample.

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Find the value of y when x=0 using the equation y=-2/3x +4

prisoha [69]

Answer:

y=4

Step-by-step explanation:

y=-2/3x+4

y=-2/3(0)+4

y=0+4

y=4

4 0

3 years ago

Martin throws a ball straight up in the air. the equation h(t) = -16t^2 + 40t + 5 gives the height of the ball, in feet, t secon

Lisa [10]

Answer:

2.62 seconds

Step-by-step explanation:

Let

t ----> the time in seconds

h(t) ----> he height of the ball, in feet

we have

$h(t)=-16t^2+40t+5$

we know that

When the ball hits the ground, the height is equal to zero

$-16t^2+40t+5=0$

The formula to solve a quadratic equation of the form

$at^{2} +bt+c=0$

is equal to

$t=\frac{-b\pm\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$-16t^2+40t+5=0$

$a=-16\\b=40\\c=5$

substitute in the formula

$t=\frac{-40\pm\sqrt{40^{2}-4(-16)(5)}} {2(-16)}$

$t=\frac{-40\pm\sqrt{1,920}} {-32}$

$t=\frac{-40+\sqrt{1,920}} {-32}=-0.12\ sec$

$t=\frac{-40-\sqrt{1,920}} {-32}=2.62\ sec$

therefore

The solution is t=2.62 seconds

4 0

3 years ago

F left parenthesis x right parenthesis equals 9 x cubed plus 2 x squared minus 5 x plus 4 and g left parenthesis x right parenth

Jet001 [13]

The answer is 2x(2x²+x+1).

When we subtract polynomials we combine like terms:
(9x³+2x²-5x+4)-(5x³-7x+4)

9x³-5x³=4x³
2x²- 0 = 2x²
-5x--7x=-5x+7x=2x
4-4=0

This gives us
4x³+2x²+2x

Each of these is divisible by 2, and each has an x, so we factor those out:
2x( )

4x³/2x = 2x²:
2x(2x² )

2x²/2x=x:
2x(2x²+x )

2x/2x = 1:
2x(2x²+x+1)

3 0

3 years ago

A and B working together can do a work in 6 days. If A takes 5 days less than B to finish the work, in how many days B alone can

svetlana [45]

Answer:

15 days

Step-by-step explanation:

Let x be the number of days needed for B to complete the job. Then x-5 is the number of days needed for A to complete the job.

In 1 day,

A completes $\dfrac{1}{x-5}$ of all work;
B completes $\dfrac{1}{x}$ of all work.

Hence, in 1 day both A and B complete $\dfrac{1}{x-5}+\dfrac{1}{x}$ of all work. A and B working together can do a work in 6 days. Then

$6\cdot \left(\dfrac{1}{x-5}+\dfrac{1}{x}\right)=1.$

Solve this equation:

$\dfrac{6x+6x-30}{x(x-5)}=1,\\ \\12x-30=x^2-5x,\\ \\x^2-17x+30=0,\\ \\D=(-17)^2-4\cdot 30=289-120=169=13^2,\\ \\x_{1,2}=\dfrac{17\pm 13}{2}=2,\ 15.$

If $x=2,$ then $x-5=-3$ that is impossible. So, B needs 15 days to complete the work alone.

6 0

3 years ago

What is the x-intercept of the line with the equation -2x + 1/2y = 18?

dimulka [17.4K]

-2x + (1/2)y = 18

(1/2)y = 2x + 18

y/2 = 2x + 18

y = 2*(2x + 18)

y = 2*2x + 2*18

y = 4x + 36

The x intercept is the value of x, when the y value is 0.

0 = 4x + 36

0 - 4x = 36

-4x = 36

x = 36/-4

x = -9

The x intercept is -9

I hope this helps.

6 0

3 years ago

Read 2 more answers