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Nimfa-mama [501]

3 years ago

15

Which equations support the fact that rational numbers are closed under addition?

2 answers:

Zielflug [23.3K]3 years ago

7 0

I think this first answer choice is supposed to be "1/3+1/3=2/3" (If so then that's the correct answer) and the second one answer would be √9+√9=2<span>√9</span>

Talja [164]3 years ago

5 0

Do you mean
√9 + √9 = 2√9

if so it is the answer

You might be interested in

Gekata [30.6K]

Answer:

Step-by-step explanation:

<u> 4km</u>

$\frac{3 }{27} \frac{miles}{minutes}$ * $\frac{60}{1} \frac{min}{hour}$ * $\frac{1}{.6213} \frac{km}{mile}$

4km ÷ 10.73 km/hr = .37 hr = 22.3 minutes

7 0

3 years ago

Which equation is parallel to the line LaTeX: y=\frac{1}{2}x+3y = 1 2 x + 3and passes through the point (10, -5)?

sukhopar [10]

Answer:

$Equation\ of\ line:\ y=\frac{1}{2}x-10$

Step-by-step explanation:

$Let\ the\ required\ equation\ is\ y=mx+c\\\\where\ m\ is\ the\ slope\ of\ the\ equation\ and\ c\ is\ y-intercept\\\\It\ is\ parallel\ to\ the\ equation\ y=\frac{1}{2}x+3\\\\Hence\ slope\ of\ these\ two\ lines\ will\ be\ same.\\\\Slope\ of\ y=\frac{1}{2}x+3\ is\ \frac{1}{2}\\\\Hence\ slope\ of\ y=mx+c\ is\ \frac{1}{2}\Rightarrow m=\frac{1}{2}\\\\Equation:y=\frac{1}{2}x+c\\\\Line\ passes\ through\ (10,-5).\ Hence\ this\ point\ satisfies\ the\ equation\ of\ line.\\\\-5=\frac{1}{2}\times 10+c$

$-5=-5+c\\\\c=-10$

$Equation\ of\ line:\ y=\frac{1}{2}x-10$

8 0

2 years ago

2. Carl needs 15 hours longer than Jennifer to paint a room. If they work together, they can complete the job in 4 hours. Explai

nasty-shy [4]

Answer:

Jennifer would complete the job on her own in 5 hours.

Step-by-step explanation:

Solving a quadratic equation:

Given a second order polynomial expressed by the following equation:

$ax^{2} + bx + c, a\neq0$ .

This polynomial has roots $x_{1}, x_{2}$ such that $ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})$ , given by the following formulas:

$x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}$

$x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}$

$\Delta = b^{2} - 4ac$

Rates

The together rate is the sum of their separates rate.

We have that:

Jennifer takes x hours to complete the job on her own, so her rate is 1/x.

Carl needs 15 hours longer than Jennifer, that is, 15 + x hours, so his rate is 1/(15+x).

The together rate is 1/4. So

$\frac{1}{4} = \frac{1}{x} + \frac{1}{15+x}$

$\frac{1}{4} = \frac{15 + x + x}{x(15+x)}$

$\frac{1}{4} = \frac{15 + 2x}{x(15+x)}$

Applying cross multiplication.

$x^2 + 15x = 4(15 + 2x)$

$x^2 + 15x = 60 + 8x$

$x^2 + 7x - 60 = 0$

Quadratic equation with $a = 1, b = 7, c = -60$ . So

$\Delta = 7^{2} - 4*1*60 = 289$

$x_{1} = \frac{-7 + \sqrt{289}}{2} = 5$

$x_{2} = \frac{-7 - \sqrt{289}}{2} = -12$

Since the time to complete the job has to be a positive value.

Jennifer would complete the job on her own in 5 hours.

4 0

2 years ago

2(n+5)=-2 step by step plz

Elodia [21]

Answer:

n=-6

Step-by-step explanation:

2(n+5)=-2

distribute

2(n+5)

2xn 2x5

2n+10

2n+10=-2

subtract 10 from both sides

10-10=0

-2-10=-12

2n=-12

divide each side by 2

2n/2=n

-12/2=-6

n=-6

6 0

3 years ago

What value of x is in the solution set of 2x - 3> 11 - 5x?<br> -3<br> 0<br> 02<br> 4

Oliga [24]

The value of x is 2. hope it helps!

8 0

3 years ago