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3 years ago

Q = x^2 - 15x + 56 = 0

Mathematics

2 answers:

BartSMP [9]3 years ago

8 0

Answer

X: 7
X: 8

This would be the answer

Dominik [7]3 years ago

7 0

Answer:

x = 8

x = 7

Step-by-step explanation:

Solving x2-15x+56 = 0 by the Quadratic Formula .

According to the Quadratic Formula, x , the solution for Ax2+Bx+C = 0 , where A, B and C are numbers, often called coefficients, is given by :

- B ± √ B2-4AC

x = ————————

In our case, A = 1

B = -15

C = 56

Accordingly, B2 - 4AC =

225 - 224 =

Applying the quadratic formula :

15 ± √ 1

x = —————

So now we are looking at:

x = ( 15 ± 1) / 2

Two real solutions:

x =(15+√1)/2= 8.000

or:

x =(15-√1)/2= 7.000

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The height of a triangle is 5 cm shorter than its base. If the area of the triangle is 25 cm2, find the height of the triangle.

Olin [163]

Answer:

$h = 5\ cm$

Step-by-step explanation:

Let's call B at the base of the triangle and call h at the height of the triangle. Then we know that:

The height of a triangle is 5 cm shorter than its base. This means that:

$h = B-5$ .

The area of the triangle is 25 cm²

By definition the area of a triangle is:

$A = 0.5Bh$

For this triangle we know that $A = 25\ cm^2$ and $h = B-5$ . We substitute these values in the equation and solve for B.

$25 = 0.5B (B-5)$

$0.5B ^ 2-\frac{5}{2}B-25 = 0$

Now we use the quadratic formula to solve the equation.

For an equation of the form $ax ^ 2 + bx + c = 0$ the quadratic formula is:

$B=\frac{-b\±\sqrt{b^2-4ac}}{2a}$

In this case note that: $a=0.5,\ \ b=-\frac{5}{2}\ \ c=-25$

Then:

$B=\frac{-(-\frac{5}{2})\±\sqrt{(-\frac{5}{2})^2-4(0.5)(-25)}}{2(0.5)}$

$B=\frac{\frac{5}{2}\±\sqrt{\frac{25}{4}+50}}{1}$

$B=\frac{5}{2}\±\frac{15}{2}$

The solutions are:

$B_1=\frac{5}{2}+\frac{15}{2}=10$

$B_2=\frac{5}{2}-\frac{15}{2}=-5$

For this problem we take the positive solution.

$B=10\ cm$

Now we substitute the value of B in the equation to find the height h

$h = 10-5$

$h = 5\ cm$

6 0

3 years ago

Please help i need help please

posledela

Answer:

Step-by-step explanation:

7 0

3 years ago

What is the inverse of the function f(x) = 2x – 10?

Evgesh-ka [11]

First make x the subject of f(x) = 2x - 10:-

2x = f(x) + 10

x = 1/2 f(x) + 5

mow replace x by hx) and f(x) by x:-

h(x )= 1/2 x + 5

3 0

4 years ago

Read 2 more answers

A ball is dropped from a cliff that is 135 m high.

Anna [14]

Answer:

113 feet

Step-by-step explanation:

I will assume you meant h = -4.9t^2 + 135; "t2" is incorrect.

To answer this question, to find the height of the ball after 2.1 seconds, substitute 2.1 for t in the above equation:

h(2.1) = -4.9(2.1)^2 + 135. This becomes -21.6 + 135, or 113.4.

The closest result to the height of the ball after 2.1 seconds is 113 feet.

4 0

3 years ago

*LAST QUESTION, PLEASE HURRY AND ANSWER* What is the volume of the cone below? (Use 3.14 for pi)

enyata [817]

Answer:

<h2> The third: 5.32 cubic units</h2>

Step-by-step explanation:

R = 1.52

H = 2.2

π = 3.14

$V=\frac13\pi R^2\cdot H\\\\V=\frac13\cdot3.14\cdot(1.52)^2\cdot2.2=5.3200810\overline6\approx5.32$

4 0

3 years ago