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3 years ago

Solve the system using elimination.

Mathematics

1 answer:

yan [13]3 years ago

8 0

Answer:

y=-3

Step-by-step explanation:

5x+7y=-31

(-) 5x-9y+17

-----------------

16y=-48

------------

16 16

y=-3

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An insect crawls 30 inches in 16.3 minutes. If

omeli [17]

Answer:

Step-by-step explanation:

Convert 6 hours to minutes so that 6 hours and 16. 3 minutes can be in the same units.

Since 1 hour = 60 minutes, then 6 hours = 6 x 60 minutes = 360 minutes

Since the insect has more minutes to crawl (360 minutes), then we expect more inches to be covered. Therefore, the ratio is 360 minutes to 16.3 minutes

= 360 minutes : 16.3 minutes

= 360 : 16.3

Now express the ratio as fraction and relate it with 30 inches

= 360/16.3 x 30/1

= 10800/16.3

= 662 .576687 and this is approximately 650 inches

Answer = 650 = (C)

3 0

3 years ago

To decorate 6 dozen cupcakes with red hot candies, Nan needs about 550 red hots. Which two sacks of candy would be the best buy?

olasank [31]

Answer:

Is there supposed to be a picture?

Step-by-step explanation:

4 0

3 years ago

-5(x+1)+3x=6-(4x-3) solve for x

PilotLPTM [1.2K]

Answer: x = -3

Step-by-step explanation:Step by step solution :

Step 1 :

Pulling out like terms :

1.1 Pull out like factors :

-x - 3 = -1 • (x + 3)

Equation at the end of step 1 :

Step 2 :

Solving a Single Variable Equation :

2.1 Solve : -x-3 = 0

Add 3 to both sides of the equation :

-x = 3

Multiply both sides of the equation by (-1) : x = -3

One solution was found :

x = -3

7 0

3 years ago

Help me for brainetest

Solnce55 [7]

Answer:

1 and 1/6

Step-by-step explanation:

if you simplify 6/6 is equal to 1 and the extra 1/6 is the fraction so the answer is 1 and 1/6

plz give me brainiest

5 0

3 years ago

Read 2 more answers

Rationalise the denominator of:<br>1/(√3 + √5 - √2)

Paul [167]

Step-by-step explanation:

$\large\underline{\sf{Solution-}}$

Given expression is

$\rm :\longmapsto\:\dfrac{1}{ \sqrt{3} + \sqrt{5} - \sqrt{2} }$

can be re-arranged as

$\rm :\longmapsto\:\dfrac{1}{ \sqrt{3} - \sqrt{2} + \sqrt{5} }$

$\rm \: = \: \dfrac{1}{( \sqrt{3} - \sqrt{2} ) + \sqrt{5} }$

On rationalizing the denominator, we get

$\rm \: = \: \dfrac{1}{( \sqrt{3} - \sqrt{2} ) + \sqrt{5} } \times \dfrac{( \sqrt{3} - \sqrt{2} ) - \sqrt{5} }{( \sqrt{3} - \sqrt{2} ) - \sqrt{5} }$

We know,

$\rm :\longmapsto\:\boxed{\tt{ (x + y)(x - y) = {x}^{2} - {y}^{2} \: }}$

So, using this, we get

$\rm \: = \: \dfrac{ \sqrt{3} - \sqrt{2} - \sqrt{5} }{ {( \sqrt{3} - \sqrt{2} )}^{2} - {( \sqrt{5}) }^{2} }$

$\rm \: = \: \dfrac{ \sqrt{3} - \sqrt{2} - \sqrt{5} }{3 + 2 - 2 \sqrt{6} - 5}$

$\rm \: = \: \dfrac{ \sqrt{3} - \sqrt{2} - \sqrt{5} }{5 - 2 \sqrt{6} - 5}$

$\rm \: = \: \dfrac{ \sqrt{3} - \sqrt{2} - \sqrt{5} }{ - 2 \sqrt{6}}$

$\rm \: = \: \dfrac{ - ( - \sqrt{3} + \sqrt{2} + \sqrt{5}) }{ - 2 \sqrt{6}}$

$\rm \: = \: \dfrac{- \sqrt{3} + \sqrt{2} + \sqrt{5}}{2 \sqrt{6}}$

On rationalizing the denominator, we get

$\rm \: = \: \dfrac{- \sqrt{3} + \sqrt{2} + \sqrt{5}}{2 \sqrt{6}} \times \dfrac{ \sqrt{6} }{ \sqrt{6} }$

$\rm \: = \: \dfrac{- \sqrt{18} + \sqrt{12} + \sqrt{30}}{2 \times 6}$

$\rm \: = \: \dfrac{- \sqrt{3 \times 3 \times 2} + \sqrt{2 \times 2 \times 3} + \sqrt{30}}{12}$

$\rm \: = \: \dfrac{- 3\sqrt{2} + 2 \sqrt{3} + \sqrt{30}}{12}$

Hence,

$\boxed{\tt{ \rm \dfrac{1}{ \sqrt{3} + \sqrt{5} - \sqrt{2} } =\dfrac{- \sqrt{3 \times 3 \times 2} + \sqrt{2 \times 2 \times 3} + \sqrt{30}}{12}}}$

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<h3><u>More Identities to </u><u>know:</u></h3>

$\purple{\boxed{\tt{ {(x - y)}^{2} = {x}^{2} - 2xy + {y}^{2}}}}$

$\purple{\boxed{\tt{ {(x + y)}^{2} = {x}^{2} + 2xy + {y}^{2}}}}$

$\purple{\boxed{\tt{ {(x + y)}^{3} = {x}^{3} + 3xy(x + y) + {y}^{3}}}}$

$\purple{\boxed{\tt{ {(x - y)}^{3} = {x}^{3} - 3xy(x - y) - {y}^{3}}}}$

$\pink{\boxed{\tt{ {(x + y)}^{2} + {(x - y)}^{2} = 2( {x}^{2} + {y}^{2})}}}$

$\pink{\boxed{\tt{ {(x + y)}^{2} - {(x - y)}^{2} = 4xy}}}$

6 0

3 years ago