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disa [49]
4 years ago
11

Subtitute 2x+y=7 and 3x-y=8

Mathematics
1 answer:
iogann1982 [59]4 years ago
8 0

Answer:

x = 3 , y = 1

Step-by-step explanation:

2x + y = 7

3x + y = 8

solution

2x + y = 7-----------(1)

3x - y = 8------------(2)

from equation 1

2x + y = 7

y = 7 - 2x-------------(3)

substitute equation 3 into equation 2

3x - y = 8

3x - (7 - 2x) = 8

3x - 7 + 2x = 8

3x + 2x = 8 + 7

5x = 15

divide through by the coefficient of x

5x/5 = 15/5

x = 3

to find y

substitute x into equation 1

2x + y = 7

2(3) + y = 7

6 + y = 7

y = 7 - 6

y = 1

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If you toss four fair coins, in how many ways can you obtain at least one head? Group of answer choicesA. 1/16B. 1/2C. 3/16D. 11
LenKa [72]

Answer:

The correct answer is:

15/16

Step-by-step explanation:

In a toss of four fair coin, there are possibility of 16 occurrence because a coin have an head and a tail (2).

In 4 coins, we will have : 2⁴ = 16

Let S be the sample space, then:

S = { HHHH, HHHT, HHTT, HTTT, TTTH, TTHH, TTTH, TTTT, HTHT, THTH, HHTH, HTHH, TTHT,THHT, HTTH, THTT}

Let E₁ be the event that at least one head appears:

n(E₁) = 15

∴ Pr (E₁) = n(E₁)/ n(S)

             = 15/16

3 0
3 years ago
7. Emma says that Function A and
Soloha48 [4]

Answer:

NO. Emma is not correct.

Step-by-step explanation:

✔️Initial value for Function A:

The initial value is the y-intercept of the graph. The y-intercept is the point at which the line intercepts the y-axis. From the graph given, the line intercepts the y-axis, at y = 2, when x = 0.

Initial value for Function A is therefore = 2

✔️Initial Value of Function B:

To find the initial value/y-intercept for Function B, do the following:

Using two pairs of values form the table, (2, 2) and (4, 3), find the slope:

Slope (m) = ∆y/∆x = (3 - 2) / (4 - 2) = 1/2

Slope (m) = ½

Next, substitute (x, y) = (2, 2) and m = ½ into y = mx + b, to find the intial value/y-intercept (b).

Thus:

2 = ½(2) + b

2 = 1 + b

2 - 1 = b

1 = b

b = 1

The initial value for Function B = 1

✅The initial value for Function A (2) is not the same as the initial value for Function B (1). Therefore, Emma is NOT CORRECT.

4 0
3 years ago
Please help me with the circled ones !
TiliK225 [7]

i can only help you with the volume of #5.

So the volume of a cylinder is = πr²h.

First , put the numbers in the equation.

π(6)² (14)

Next you solve.

π(6)²(14) = 36 (14) π = 504π


V= 504π

4 0
3 years ago
Find the constant of variation k for the direct variation ​
Alla [95]

Answer:

The constant of variation is k = -2 ⇒ (B)

Step-by-step explanation:

The equation of the direct variation is y = k x, where

  • k is the constant of variation
  • The constant of variation k = \frac{y}{x}

The given table has 4 points (-1, 2), (0, 0), (2, -4), (5, -10)

We can use one of the points <em>[except point (0, 0)]</em> to find the value of k

∵ (-1, 2) is a given point

∴ x = -1 and y = 2

∵ k = \frac{y}{x}

→ Substitute the values of x and y in the relation above

∴ k = \frac{2}{-1}

∴ k = -2

The constant of variation is k = -2

7 0
3 years ago
Solve -5w = -80 for w.<br><br> w =
Aleks [24]

Answer:

w=4

Step-by-step explanation:

-80/-5=4

6 0
3 years ago
Read 2 more answers
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