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2 years ago

Please help with this question asap it’s a test

Mathematics

2 answers:

UkoKoshka [18]2 years ago

8 0

-4x + 9 = 28
-4x = 28 - 9
-4x = 19
x = -4.75

Andre45 [30]2 years ago

6 0

Answer

Step-by-step explanation:

I really not sure if to add 4x or to minus 9

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una ventana rectangular tiene l metros de ancho y h metros de altura, con un perímetro de 6 metros y un área de 2m² ¿cuál es la

seropon [69]

Answer:

The formula for calculating the width of the window is

$w=\frac{-(-3)(+/-)\sqrt{-3^{2}-4(1)(2)}} {2(1)}$

Step-by-step explanation:

<u><em>The question in English is</em></u>

A rectangular window is l meters wide and h meters high, with a perimeter of 6 meters and an area of 2m². What is the formula for calculating the width of the window?

we know that

The perimeter of the window is equal to

$P=2(l+w)$

we have

$P=6\ m$

$6=2(l+w)$

simplify

$3=(l+w)$

isolate the variable l

$l=3-w$ ----> equation A

The area of the window is equal to

$A=lw$

we have

$A=2\ m^2$

$2=lw$ ----> equation B

substitute equation A in equation B

$2=(3-w)w$

solve for w

$2=3w-w^2$

$w^2-3w+2=0$

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$w^2-3w+2=0$

$a=1\\b=-3\\c=2$

substitute in the formula

$w=\frac{-(-3)(+/-)\sqrt{-3^{2}-4(1)(2)}} {2(1)}$ ---> formula for calculating the width of the window

$w=\frac{3(+/-)\sqrt{1}} {2}$

$w=\frac{3(+/-)1} {2}$

$w=\frac{3(+)1} {2}=2\ m$

$w=\frac{3(-)1} {2}=1\ m$

7 0

3 years ago

A rectangular piece of metal is 15 in longer than it is wide. Squares with sides 3 in long are cut from the four corners and the

ziro4ka [17]

Answer:

The original dimensions of the piece of metal are

Length: 36 inches

Width: 21 inches

Step-by-step explanation:

Let

x ----> the original length pf the piece of metal

y ----> the original width pf the piece of metal

we know that

$x=y+15$ ----> equation A

The volume of the box is equal to

$V=LWH$

we have

$V=1,350\ in^3$

$L=(x-3-3)=(x-6)\ in\\W=(y-3-3)=(y-6)\ in$

$H=3\ in$

substitute in the formula of volume

$1,350=(x-6)(y-6)(3)$ ----> equation B

substitute equation A in equation B

$1,350=(y+15-6)(y-6)(3)$

solve for y

$450=(y+9)(y-6)$

$y^2-6y+9y-54=450\\y^2+3y-504=0$

Solve the quadratic equation by graphing

using a graphing tool

The solution is y=21

Find the value of x

$x=21+15=36$

therefore

The original dimensions of the piece of metal are

Length: 36 inches

Width: 21 inches

5 0

2 years ago

What's one fifth of 45

pishuonlain [190]

1 /5 = 0 . 2
45 * . 2 = 9
Hope this helped :)

3 0

3 years ago

Read 2 more answers

When you add the same number to each side of an equation, do you always get an equivalent equation? webasign?

CaHeK987 [17]

Yes you always do.

eg x - 2 = 8

x - 2 + 2 = 8 + 2

x = 10
if we plug x = 10 into the original equation we se that this fits:-

10 - 2 = 8

8 0

3 years ago

Pass a brotha some help :(

nikitadnepr [17]

Answer and Step-by-step explanation:

Distribute the 1p to the y and -6 and distribute the 2 to the 3y and 6.

10y - 50 + 6y + 12

Now, combine like terms.

16y - 38

#teamtrees #PAW (Plant and Water)

7 0

2 years ago