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2 years ago

Solve the system by graphing. {-2x=2y-4, 2x-y=-5

Mathematics

1 answer:

Phantasy [73]2 years ago

5 0

x=(2y-4)/-2

x=-y+2

2(-y+2)-y=-5

-2y+4-y=-5

-3y+4=-5

-3y=-9

y=3

x=-y+2

x=-3+2

x=-1

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The length of a rectangle is one unit more than the width. if the area is 30 square units find the dimensions of the rectanhgle

solmaris [256]

Width = w

Length = w + 1

Area = 30

w(w+1) = 30

w² + w = 30

w² + w - 30 = 0

w² + 6w - 5w - 30 = 0

w(w + 6) -5(w + 6) = 0

(w + 6)(w - 5) = 0

w = 5 or -6

Since the width cannot be negative, the width is 5 units.

Hence, the width is 5 units and the length is 6 units.

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2 years ago

Perimeter of rectangle is 48 inches area is 40 inches what are the length of the side

Aloiza [94]

$\bf \textit{perimeter of a rectangle}=p=side+side+side+side
\\\\
or\implies p=w+w+l+l\implies p=2w+2l
\\\\
p=2(w+l)\qquad 
\begin{cases}
w=width\\
l=length\\
------\\
p=48
\end{cases}\implies 40=2(w+l)\\\\
-----------------------------\\\\
\textit{area of it}=A=w\cdot l\qquad \begin{cases}
w=width\\
l=length\\
------\\
A=40
\end{cases}\implies 40=wl\\\\
-----------------------------\\\\$

$\bf thus\qquad 
\begin{cases}
40=2(w+l)\to \frac{40}{2}=w+l\to\frac{40}{2}-l=\boxed{w}
\\\\
40=wl\\
--------------\\
40=\left( \boxed{\frac{40}{2}-l} \right)\cdot l
\end{cases}$

solve for "l" to find its length

7 0

2 years ago

I need help on this one please

katrin2010 [14]

Answer:

Step-by-step explanation:

(-2,4), (0,6), and(2,8)

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2 years ago

Factor both quadratic expressions. (x 4 + 5x 2 - 36)(2x 2 + 9x - 5) = 0

Sonbull [250]

So focusing on x^4 + 5x^2 - 36, we will be completing the square. Firstly, what two terms have a product of -36x^4 and a sum of 5x^2? That would be 9x^2 and -4x^2. Replace 5x^2 with 9x^2 - 4x^2: $x^4+9x^2-4x^2-36$

Next, factor x^4 + 9x^2 and -4x^2 - 36 separately. Make sure that they have the same quantity inside of the parentheses: $x^2(x^2+9)-4(x^2+9)$

Now you can rewrite this as $(x^2-4)(x^2+9)$ , however this is not completely factored. With (x^2 - 4), we are using the difference of squares, which is $a^2-b^2=(a+b)(a-b)$ . Applying that here, we have $(x+2)(x-2)(x^2+9)$ . x^4 + 5x^2 - 36 is completely factored.

Next, focusing now on 2x^2 + 9x - 5, we will also be completing the square. What two terms have a product of -10x^2 and a sum of 9x? That would be 10x and -x. Replace 9x with 10x - x: $2x^2+10x-x-5$

Next, factor 2x^2 + 10x and -x - 5 separately. Make sure that they have the same quantity on the inside: $2x(x+5)-1(x+5)$

Now you can rewrite the equation as $(2x-1)(x+5)$ . 2x^2 + 9x - 5 is completely factored.

<h3><u>Putting it all together, your factored expression is $(x+2)(x-2)(x^2+9)(2x-1)(x+5)=0$ </u></h3>

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2 years ago

The sum of the area of 2 circles is 80pi square meters. Find the length of a radius of each circle if one of them is twice as lo

IgorC [24]

80p=pr^2+p(2r)^2
80p=pr^2+4pr^2
80=r^2+4r^2
80=5r^2
16=r^2
r=4 for the smaller circle´s radius, and 8 is the larger circle´s radius.

Have a nice day, I hope this was helpful :D

8 0

2 years ago

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