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3 years ago

3x+y=4 x+2y=-2 what is the answer

Mathematics

1 answer:

Taya2010 [7]3 years ago

3 0

Answer:

2(3x+y=4)

1(x+2y=-2)

6x+2y=8

(-) x+2y=-2

5x=10

x=2

x+2y=-1

2+2y=-1

-2 -2

2y=-3

y=-3/2

Step-by-step explanation:

multiply the first equation by 2 to make y equal to each other.
subtract to eliminate y
divide by 5 to get x
take one of the equations
replace x by 2 to solve for y

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What is the smallest 6 digit palindrome that is divisible by 99

Scorpion4ik [409]

Answer:

108801

Step-by-step explanation:

6-digit palindrome is the number n the form of:

xyzzyx

This is divisible by 11 by default as the sum of the digits in odd placed is same as sum of the number in even places (remember the divisibility rule by 11):

x + z + y = y + z + x

Now, in order to be divisible by 99, the number must be divisible by 11 and 9.

According to divisibility rule by 9 the sum of all digits must be divisible by 9. You can see In our case we need to have (the minimum):

x + y + z = 9

The smallest number we could get is when x is minimum, y is minimum, so:

x = 1, y = 0, then y = 8

The number we get is:

108801

Proof:

108801/99 = 1099

4 0

2 years ago

Read 2 more answers

Which fraction is NOT equivalent to 4/9 ?

BARSIC [14]

Everything that is not 4/9

8 0

2 years ago

Read 2 more answers

At 3:30 p.m., Berto’s train was 34 miles past the egg farm, traveling at an average speed of 85 miles per hour. At the same time

timurjin [86]

E=egg farm

x=distantce between the Berto´s trains and the meeting point.

t=time where the trains meet up

⇒110 miles/h ⇒85miles/h

[---------------------------E----------------------]-------------------------------------X

[............12 miles.......][........34 miles.....][------------ x ----------------------]

distance between Berto´s train and Eduardo´s train=

=12 miles+34 miles=46 miles.

S=d/t ⇒d=S*t

S=seed

d=distance

T=time

Eduardo´s train;

46 miles+x=t*110 miles/h ⇒x=t*110 miles/h-46 miles (1)

Berto´s train;

x=t*85 miles/h (2)

With the equations (1) and (2) we suggest this system equations:

x=t* 110 miles/h-46 miles

x=t*85 miles/h

we solve this system equiations :

t*110 miles/h-46 miles=t*85 miles/h

110t miles/h-85t miles/h=46 miles

25 t miles/h=46 miles

t=46 miles/25 miles/h=1,84 hour (≈1 hour, 50 minutes, 24 seconds)

x=t*85 miles/h=156,4 miles

Solution: 1,84 hour

3 0

3 years ago

Read 2 more answers

A rectangular box is to have a square base and a volume of 12 ft3. If the material for the base costs $0.17/ft2, the material fo

katen-ka-za [31]

Answer:

(a)Length =2 feet

(b)Width =2 feet

(c)Height=3 feet

Step-by-step explanation:

Let the dimensions of the box be x, y and z

The rectangular box has a square base.

Therefore, Volume of the box $V=x^2z$

Volume of the box $=12 ft^3\\$

$Therefore, x^2z=12\\z=\frac{12}{x^2}$

The material for the base costs $\$0.17/ft^2$ , the material for the sides costs $\$0.10/ft^2$ , and the material for the top costs $\$0.13/ft^2$ .

Area of the base $=x^2$

Cost of the Base $=\$0.17x^2$

Area of the sides $=4xz$

Cost of the sides= $=\$0.10(4xz)$

Area of the Top $=x^2$

Cost of the Base $=\$0.13x^2$

Total Cost, $C(x,z) =0.17x^2+0.13x^2+0.10(4xz)$

Substituting $z=\frac{12}{x^2}$

$C(x) =0.17x^2+0.13x^2+0.10(4x)(\frac{12}{x^2})\\C(x)=0.3x^2+\frac{4.8}{x} \\C(x)=\dfrac{0.3x^3+4.8}{x}$

To minimize C(x), we solve for the derivative and obtain its critical point

$C'(x)=\dfrac{0.6x^3-4.8}{x^2}\\Setting \:C'(x)=0\\0.6x^3-4.8=0\\0.6x^3=4.8\\x^3=4.8\div 0.6\\x^3=8\\x=\sqrt[3]{8}=2$

Recall: $z=\frac{12}{x^2}=\frac{12}{2^2}=3\\$

Therefore, the dimensions that minimizes the cost of the box are:

(a)Length =2 feet

(b)Width =2 feet

(c)Height=3 feet

7 0

2 years ago

I need someone to help me with this question?

-Dominant- [34]

AAB I think that's it get back to me If its wrong

6 0

3 years ago