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2 years ago

This is a similar triangle please find the missing length. (?)

Mathematics

1 answer:

stira [4]2 years ago

3 0

Answer:

Step-by-step explanation:

Set up as a proportion:

$\frac{QR}{QP}=\frac{BA}{BC}$ , insert given values

$\frac{?}{12}=\frac{30}{36}$ , cross multiple

36*?=30*12

36*?=360, divide both sides by 36 to get the missing side (?) by itself

?=10

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Help with matrice equations

Tasya [4]

Answer:

21) x=1, y=-1, z=2 and 23) x=3, y=-1, z=-1

Step-by-step explanation:

there are 3 equations in 21)

1) x+y-z=-2

2)2x-y+z=5

3)-x+2y+2z=1

solve for x by adding equation 2) and 1)

2)2x-y+z=5 + 1) x+y-z=-2 = 3x=3, then divide by 3 and x=1

solve for z by adding equation 1) and 3)

1) x+y-z=-2 + 3)-x+2y+2z=1

we then get a new equation, 4), by isolating z

3y+z=-1 which is 4) z=-1-3y

substitute our new equation, 4) z=-1-3y, and x=1 into equation 1) to get y

(1)+y- (-1-3y)=-2

isolate y to get y=-1

then substitute y=-1 into equation 4) to get z=2

check by substituting x=1, y=-1, and z=2 into all 3 equations

there are 3 equations

1)x+3y=0

2)x+y+z=1

3)3x-y-z=11

add equation 3) and 2) together to get x

3)3x-y-z=11 + 2)x+y+z=1

4x=12, x=3

substitute x=3 into equation 1) (3)+ 3y=0 to get y

3y=-3, y=-1

substitute x=3 and y=-1 into equation 2) to get z

(3)+(-1)+z=1, z=-1

4 0

3 years ago

Determine the average speed of the current in a river if a boat moves at 20 miles/hour in still water and takes 3 hours to trave

Taya2010 [7]

The speed of the current in a river is 6 miles per hour

Solution:

Given that,

Speed of boat in still water = 20 miles per hour

Time taken = 3 hours

Distance downstream = 78 miles

To find: Speed of current

If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then:

Speed downstream = (u + v) km/hr

Speed upstream = (u - v) km/hr

Therefore, speed downstream is given as:

$\text{ speed downstream } = \frac{distance}{time} = \frac{78}{3}\\\\\text{ speed downstream } = 26 \text{ miles per hour }$

We know that,

Speed downstream = (u + v)

26 = 20 + v

v = 26 - 20

v = 6 miles per hour

Thus speed of the current in a river is 6 miles per hour

3 0

3 years ago

PLEASE HELP!!!!!!!!!!!!1

skelet666 [1.2K]

A. Let x = cheese and
y = chocolate
2x + y = 25
x + y = 20

B. Subtract the second equation from the first.
2x + y = 25
-(x + y = 20)
-—————
x = 5

Plug 5 back in to the second equation and solve for y.
x + y = 20
5 + y = 20
Subtract 5 from both sides.
y = 15
5 cheese and 15 chocolate

Used elimination method because coefficients on the y values were both 1 so it was easy to subtract the equations and eliminate the y variable.

5 0

3 years ago

Which line corresponds to y=2x+5? *please see picture* *serious answers only*

Ivahew [28]

Answer:

Step-by-step explanation:

the one on the tight becasue try plugging in zero

8 0

3 years ago

Read 2 more answers

Identify whether the series is a convergent or divergent geometric series and find the sum, if possible. A) This is a convergent

Darya [45]

A divergent series is a type of series in which the ratio is too large and the summation is held from one to infinity. Hence, the sum could not be found out. A convergent series, on the other hand, has a definite answer because one could be the ratio is small and the lower and upper limits are defined not equal to infinity either positive or negative.

7 0

3 years ago