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3 years ago

5 times the sum of 12 and a number is 80 What is the value of the unknown number

Mathematics

1 answer:

kirill115 [55]3 years ago

3 0

Answer:

Step-by-step explanation:

5(12+x)=80 Create equation. x is the unknown number.

60+5x=80 Distributive property.

5x=20 Isolate variable.

x=4 Divide on both sides by the coefficient.

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Fatoring Trinomials<br> x^2+2x=-1

Musya8 [376]

Answer:

$\Huge \boxed{x=-1}$

Step-by-step explanation:

$x^2+2x=-1$

Adding 1 to both sides of the equation.

$x^2+2x+1=-1+1$

$x^2 +2x+1=0$

Factoring the left side of the equation.

$x^2 +1x+1x+1=0$

$x(x+1)+1(x+1)=0$

$(x+1)(x+1) = 0$

$(x+1)^2 =0$

Taking the square root of both sides of the equation.

$\sqrt{(x+1)^2} =\sqrt{0}$

$x+1=0$

Subtracting 1 from both sides of the equation.

$x+1-1=0-1$

$x=-1$

8 0

3 years ago

Read 2 more answers

Jacob is playing a game where he earns 3 points for a correct answer and loses 2 points for an incorrect answer. He currently ha

Sveta_85 [38]

I think c

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Solve the formula 2x+3y=12 for y

rjkz [21]

Answer:

y=4−2x/3

Step-by-step explanation:

Move all terms that don't contain y to the right side and solve.

3 0

2 years ago

I am thinking of a 3-digit number.

koban [17]

Answer:

The answer is 939

Step-by-step explanation:

If you divide 939 by 9 it equals 104 R3.

If you divided 939 by 2 it equals 469 R1

And if you divide 939 by 5 it equals 187 R4

Hope this helps!

7 0

3 years ago

A written explanation solving the question how much fluid is needed using the Pythagorean method and finding the area of the tri

Alecsey [184]

Answer:

793 liters of washing fluid is needed

Step-by-step explanation:

step 1

Find the slant height of the triangular faces of pyramid

we know that

The lateral area of a square pyramid is equal to the area of its four triangular faces

$LA=4[\frac{1}{2}bl]$

where

b is the base of triangle (is the same that the length of the square base)

l is the slant height

To find out the slant height we need to apply the Pythagorean Theorem

$l^2=(b/2)^2+h^2$

we have

$b=35.42\ m$

$h=21.64\ m$

substitute

$l^2=(35.42/2)^2+21.64^2$

$l^2=781.9337$

$l=27.96\ m$

step 2

Find the lateral area of the pyramid

$LA=4[\frac{1}{2}bl]$

we have

$l=27.96\ m$

$b=35.42\ m$

substitute

$LA=4[\frac{1}{2}(35.42)(27.96)]$

$LA=1,980.6864\ m^2$

step 3

Find out how much window washing fluid is needed

we know that

2 L of washing fluid cover 5 square meters

using proportion

$\frac{2}{5}\ \frac{L}{m^2}=\frac{x}{1,980.6864}\ \frac{L}{m^2}\\\\x=1,980.6864(2)/5\\\\x= 792.27\ L$

Round up

793 liters of washing fluid is needed

6 0

3 years ago