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4 years ago

Solve the system of equations using elimination. 4x - 7y = 5 8x + 3z = -35 6y + 3z = 15

Mathematics

2 answers:

9966 [12]4 years ago

8 0

Answer:

x = -11.88 y = -7.5 z =20

Step-by-step explanation:

8x -6y = -50

-2( 4x -7y = 5 )

8x -6y = -50

-8x +14y = -10

8y= -60

y= -7.5

4x -7(-7.5) = 5

4x + 52.5 = 5

4x = -47.5

x= -11.88

6(-7.5) +3z = 15

-45 +3z = 15

45 45

3z = 60

z= 20

Angelina_Jolie [31]4 years ago

4 0

Answer:

x=-5/8, y=15/2, z=-10. (-5/8, 15/2, -10).

Step-by-step explanation:

4x-7y=5

8x+3z=-35

6y+3z=15

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

4x=7y+5

2(4x)=2(7y+5)

8x=14y+10

14y+10+3z=-35

14y+3z=-35-10

14y+3z=-45

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

14y+3z=-45

6y+3z=15

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

14y+3z=-45

-(6y+3z)=-15

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

14y+3z=-45

-6y-3z=-15

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

8y=-60

simplify,

y=15/2

6(15/2)+3z=15

45+3z=15

3z=15-45

3z=-30

z=-30/3

z=-10

8x+3(-10)=-35

8x-30=-35

8x=-35+30

8x=-5

x=-5/8

x=-5/8, y=15/2, z=-10.

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The volume of a sphere is 36 cubic inches. What is the radius of the sphere?

Serjik [45]

Answer:

2.05 inches

Step-by-step explanation:

V = 4/3 x πr³

36=4πr³/3

36x3= 4πr³

108= 4πr³

108/4 = πr³

27= πr^3

27/π =r³

$\sqrt[3]{27 \div \pi}$

r= 2.048in

round off to 2.05in

PROOF

V = 4÷3 x πr³

V= 4/3 x π(2.05)³

V=4/3 x π8.6

V=4×π×8.6/3

V=108/3

V=36in³

Therefore: radius= 2.05 inches

8 0

3 years ago

Solve the system equation

den301095 [7]

<h2>Answer:</h2>

We will use substitution to solve this system for x.

$x - 2y = 27\\y = 5x\\\\x - 2(5x) = 27\\\\x - 10x = 27\\\\-9x = 27\\\\x = -3$

Now that we know what x is, we can determine y by pluging in -3 for x in one of the original equations. I will use the first one.

$-3 - 2y = 27\\\\-2y = 30\\\\y = -15\\$

We now have our solution.

D. $(-3, -15)$

We can check our answer by pluging the solution into one of the original equations to see if both sides equal each other. I will use the first equation.

$-3 - 2(-15) = 27\\\\-3 + 30 = 27\\\\27 = 27$

Since the equation checks out, our solution is correct.

4 0

3 years ago

The hours of daylight, y, in Utica in days x from January 1, 2013 can be modeled by the equation y = 2.89sin(0.0145x-1.40) + 10.

Pie

Answer:

9.3 hours

Step-by-step explanation:

Given

$y = 2.89\sin(0.0145x-1.40) + 10.99.$

Required

Hours of sunlight on Feb 21, 2013

First, calculate the number of days from Jan 1, 2013 to Feb 21, 2013

$days = 52$

So:

$x = 52$

So, we have:

$y = 2.89\sin(0.0145x-1.40) + 10.99.$

$y = 2.89\sin(0.0145*52-1.40) + 10.99.$

$y = 2.89\sin(0.754-1.40) + 10.99.$

$y = 2.89\sin(-0.646) + 10.99.$

$y = 2.89*-0.6020 + 10.99.$

$y = -1.740 + 10.99.$

$y = 9.25$

$y = 9.3$ --- approximated

8 0

3 years ago

Expand and simplify these 6 questions

zhuklara [117]

First one: divide multiply 2(1x) which would equal 2x then do 2*3 then u would subtract 5 which should get you to the simplified form 2x+1

Second one: do 3(1x) which would equal 3x then do 7*3 which would equal 21 than do plus 3x which should get you to the simplified form of 6x+21

Third one: Do 4(1x) which equals 4x than do 4*2 which equals 8 than plus eight which should get you to the simplest form of 4x+16

Fourth one: do 4(1x) which would equal 4x then do 4*1 which equals 4 than subtract 6 which should get you to the simplest form of 4x-2

Fifth one: do 2(3x) which equals 6x then do 2*2 which equals 4 than subtract 5x which should get you to the simplest form of x+4

Sixth one: do 5(1x) which equals 5x than do 5*-4 which equals -20 than add 10 which gets you to the simplest form of 5x-10

3 0

3 years ago

Students at Maple school earned $708 selling candles. They want to accumulate $2000 for a club trio. What percent of their goal

Sholpan [36]

Answer:

The correct answer is 35.4%

Step-by-step explanation:

Let's check the information provided in the question:

Savings goal = US$ 2,000 for the club trip

Earnings for the candles selling = US$ 708

For calculating the accumulated percentage, we can do it this way:

Accumulated percentage = Earnings / Savings goal

Accumulated percentage = 708 / 2,000 * 100

Accumulated percentage = 0.354 * 100

Accumulated percentage = 35.4%

Students at Maple School has accumulated 35.4% of their savings goal with the candles selling.

5 0

3 years ago