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3 years ago

The tens digit is two less than the ones digit and sum of the digits is 8.

Mathematics

2 answers:

Pepsi [2]3 years ago

8 0

The answer is 35 !!!

Agata [3.3K]3 years ago

7 0

Answer:

Step-by-step explanation:

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Please help me out!

seropon [69]

Answer:

Second option

Third option

Fourth option

Step-by-step explanation:

We have the following quadratic function

$f(x) =(x-1)(x+7)$

Use the distributive property to multiply the expression

$f(x) =x^2+7x-x-7$

$f(x) =x^2+6x-7$

For a function of the form $f (x) = ax ^ 2 + bx + c$ the x coordinate of the vertex is:

$x =-\frac{b}{2a}$

Then in this case the coordinate of the vertex is:

$x =-\frac{6}{2(1)}$

$x =-3$

To obtain the y coordinate of the vertex we evaluate the function at $x = -3$

$f(-3) =(-3)^2+6(-3)-7$

$f(-3) =9-18-7$

$f(-3) =-16$

Then the vertex is: (-3, -16)

We can see in the graph that the zeros of the function are x=1 and x=-7

Then the function is decreasing from -∞ to -3 and then it is increasing from -3 to ∞

The function is positive for $x$ and $x> 1$

The correct answers are:

Second option

Third option

Fourth option

7 0

3 years ago

points P and Q lie 240 m apart in line with and on opposite sides of a communications tower. the angles of elevation to the top

Leona [35]

Answer:

The height of the tower is 130.5m

Step-by-step explanation:

In the question, we are given the following values:

The angles of elevation to the top of the tower from P = 50°

The angles of elevation to the top of the tower from Q = 45°

The angles of elevation to the top of the tower from P = 50°

Hence,cot P = 1/ tan(50°)

The angles of elevation to the top of the tower from Q = 45°

Hence, tan 45° = 1

In the question,we are told Points P and Q lie 240 m apart in line with and on opposite sides of a communications tower.

Therefore,

PQ = height of the tower( tan Q + 1/tan P)

240m = height of the tower( tan 45° + 1/ tan 50°)

240m = h(1 + 1/tan 50°)

h = (240 m)/(1 + 1/tan (50°))

h = 130.49863962 meters

Therefore, the height of the tower to the nearest tenth of a meter is 130.5 meters(m)

5 0

3 years ago

$570, 2%, 6 months <br> -<br> Help, I don’t get how to do it.

Phantasy [73]

Answer:

$641.91

Step-by-step explanation:

A(t) = 570(1+0.02)^6

8 0

2 years ago

Solve 5(7)5x = 60. Round your answer to the nearest thousandth.<br> X

solong [7]

5(7)5x=60

35*5x=60

175x=60

x=60/175

x= 0.342

Enjoy and your answer is 0.342

5 0

2 years ago

(1 point) Linear System - Three Variables Solve the following system of equations using Gaussian elimination method. If there ar

EastWind [94]

Answer:

$x=\frac{-363}{70}$ ≈ -5.1857

$y=\frac{-192}{35}$ ≈ -5.4857

$z=\frac{313}{84}$ ≈ 3.7262

Step-by-step explanation:

Rewrite the equation system as:

$6x+8y=-75$

$-3x+6y+6z=5$

$2x-9y=39$

Now, write the system in its augmented matrix form:

$\left[\begin{array}{cccc}6&8&0&-75\\-3&6&6&5\\2&-9&0&39\end{array}\right]$

applying row reduction process to its associated augmented matrix:

Swap R1 and R3, and then Swap R1 and R2:

$\left[\begin{array}{cccc}-3&6&6&5\\2&-9&0&39\\6&8&0&-75\end{array}\right]$

R3+2R1

$\left[\begin{array}{cccc}-3&6&6&5\\2&-9&0&39\\0&20&12&-65\end{array}\right]$

3R2+2R1

$\left[\begin{array}{cccc}-3&6&6&5\\0&-15&12&127\\0&20&12&-65\end{array}\right]$

15R3+20R2

$\left[\begin{array}{cccc}-3&6&6&5\\0&-15&12&127\\0&0&420&1565\end{array}\right]$

Now we have a simplified system:

$-3x+6y+6z=5\\0-15y+12z=127\\0+0+420z=1565$

$-3x+6y+6z=5\hspace{5 mm}(1)\\0-15y+12z=127\hspace{3 mm}(2)\\0+0+420z=1565\hspace{3 mm}(3)$

From (3):

$z=\frac{313}{84}$ (4)

Replacing (4) in (2)

$y=\frac{-192}{35}$ (5)

Finally replacing (5) and (4) in (1)

$x=\frac{-363}{70}$

7 0

3 years ago