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3 years ago

What are the mental math steps to find 7(42)

Mathematics

1 answer:

Kaylis [27]3 years ago

8 0

7*40 = 280, 7*2 = 14,
add both and get 280+14 = 294

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Aflati triunghiul dreptunghic ABC daca a) a=17 si b=8 b) c=6 C=42 grade

Ierofanga [76]

Answer is c c=42 grade

7 0

4 years ago

The area of the regular octagon is approximately 54 cm2. What is the length of line segment AB, rounded to the nearest tenth?

erastova [34]

Answer:

AB = 3.3 cm

Step-by-step explanation:

The formula to find out area of a regular octagon is given by

$A=2(1+\sqrt{2})a^{2}$

where a is the length of each side of the regular octagon.

Plugin A=54 into the formula

$54=2(1+\sqrt{2})a^{2}$

Divide both sides by 2

$\frac{54}{2} =\frac{2}{2} (1+\sqrt{2})a^{2}$

$27 = (1+\sqrt{2})a^{2}$

Plugin √2 as 1.41

$27 = (1+1.41)a^{2}$

$27 = (2.41)a^{2}$

Divide both sides by 2.41

$\frac{27}{2.41} = \frac{2.41}{2.41} a^{2}$

$11.20 = a^{2}$

Taking square root on both sides

$\sqrt{11.20} = \sqrt{a^{2}}$

a = 3.346

a = 3.3 cm (rounded to nearest tenth)

so, length of side AB = 3.3 cm

6 0

3 years ago

Read 2 more answers

X-2y/12y^2-x+4y/12y^2 simplify

Anon25 [30]

(2x+2y)/(12y^2) would be the simplist

3 0

4 years ago

Find the domain over which the function y = x + 6x is monotonic increasing.

iragen [17]

Answer:

x > -3

$\sf (-3, \infty)$

Step-by-step explanation:

Domain: input values (x-values)

Monotonic increasing: always increasing.
A function is increasing when its graph rises from left to right.

The graph of a quadratic function is a parabola. If the leading term is positive, the parabola opens upwards. The domain over which the function is increasing for a parabola that opens upwards is values greater than the x-value of the vertex.

Vertex

Standard form of quadratic equation: $\sf y=ax^2+bx+c$

$\textsf{x-value of vertex}=\sf -\dfrac{b}{2a}$

Given function:

$\sf y=x^2+6x$

Therefore, x-value of function's vertex:

$\sf \implies x= -\dfrac{6}{2}=-3$

Final Solution

The function is increasing when x > -3

$\sf (-3, \infty)$

4 0

3 years ago

The sets of numbers 3, 4, 5, and 8, 15, 17 are Pythagorean triples. Use what you know about the Pythagorean Theorem and explain

Leviafan [203]

Answer:

Pythagorean Theorom: a^2+b^2=c^2

Take the largest number of each as C (hypotenuse)

3,4,5

(3)^2+(4)^2= (5)^2

25=25

Therefore it is a Pythagorean Triple.

8,15,17

(8)^2+(15)^2=(17)^2

289=289

Therefore it is a Pythagorean Triple.

7 0

4 years ago