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BabaBlast [244]
3 years ago
7

How does the associative property of multiplication help you to calculate products mentally?

Mathematics
1 answer:
notka56 [123]3 years ago
6 0
For example, evaluate 17*5*20:
Method 1: (17*5)*20 = 85*20 = 1,700.
Method 2: 17*(5*20) = 17*100 = 1,700.
Notice that by first multiplying 5*20 to get 100, the calculation
is easy to do in your head.
You can also use the commutative property to rearrange a question:
5*21*4 = 5*4*21 = 20*21 = 420
You might be interested in
The park is 6 mi due east of Freeport High School, and the library is 4 mi due west of the school. The police department is loca
AURORKA [14]
The answer is 6.7 mi.

Since the right triangle is present, to calculate this we will use the Pythagorean theorem. According to the Pythagorean theorem, the square of the hypotenuse (c²) is equal to the sum of the squares of two other sides (a² + b²)<span>:
c</span>² = a² + b²<span>

First, we need to express symbols:
b - side of the right triangle (distance </span><span>between police department and Freeport High School).
a1 - </span>side of the first right triangle (distance between library and Freeport High School).<span>
a2 - </span><span>side of the second right triangle (distance between park and Freeport High School).
c1 - hypotenuse of the first triangle (distance between </span>police<span> department and library).
c2 - </span>hypotenuse of the second triangle (distance between police<span> department and park).

Therefore, we need to calculate c2.
It is given:
a2 = 6 mi
a1 = 4 mi
c1 = 5 mi

First, let's calculate b, which is a common side for two triangles:
</span>c1<span>² = a1² + b²
</span>b² = c1<span>² - a1²
</span>b² = 5<span>² - 4²
</span>b² = 25<span> - 16
</span>b² = 9
√b² = √9
b = 3.

We know b, now we can calculate c2:
c2<span>² = a2² + b²
</span>c2<span>² = 6² + 3²
</span>c2<span>² = 36 + 9
</span>c2<span>² = 45
</span>√c2<span>² = </span>√45
c2 = 6.7

The distance between police department and park is 6.7 miles.

3 0
3 years ago
Please ANSWER CORRECTLY BRAINIEST WILL BE GIVEN !!!!!
neonofarm [45]
Area = lxb
        =(5x - 4) x (2x - 5)
        =10x*2 - 25x - 8x + 20
        =10x*2 -33x +20

so b is correct option and give me brainliest

6 0
3 years ago
Read 2 more answers
Find the volume of the cone shown as a decimal rounded to the nearest tenth.
Makovka662 [10]

Answer:

<h2> a.  392.7 yd³</h2><h2 />

Step-by-step explanation:

volume = 1/3 π r² h

where h = 15 yd.

           r = 5 yd.

<u>plugin values into the equation:</u>

volume = 1/3 π r² h

            = 1/3 * π * 5² * 15

            = 392.7 yd³

3 0
3 years ago
Read 2 more answers
Simplify the expression (sqrt3+i)(sqrt3-i) and write the result in the form a+bi
rjkz [21]

Answer:

4

Step-by-step explanation:

This expression is a difference of squares.

(√3 + i)(√3 - i) = (√3)²-(i)², which is

3 - (-1)

= 3 + 1

= 4

7 0
2 years ago
What is the zero of y=-4x^2+8x-28
tangare [24]

Solution, y-4x^2+8x-28=0:\quad \mathrm{Parabola\:with\:vertex\:at}\:\left(h,\:k\right)=\left(1,\:24\right),\:\mathrm{and\:focal\:length}\:|p|=\frac{1}{16}

Steps:

\mathrm{Rewrite}\:y-4x^2+8x-28=0\:\mathrm{in\:the\:standard\:form}

\mathrm{Rewrite\:as}, y=4x^2-8x+28

\mathrm{Complete\:the\:square}\:4x^2-8x+28:\quad 4\left(x-1\right)^2+24, y=4\left(x-1\right)^2+24

\mathrm{Subtract\:}24\mathrm{\:from\:both\:sides}, y-24=4\left(x-1\right)^2

\mathrm{Divide\:by\:coefficient\:of\:square\:terms:\:}4, \frac{1}{4}\left(y-24\right)=\left(x-1\right)^2

\mathrm{Rewrite\:in\:standard\:form}, 4\cdot \frac{1}{16}\left(y-24\right)=\left(x-1\right)^2

\mathrm{Therefore\:parabola\:properties\:are:} \left(h,\:k\right)=\left(1,\:24\right),\:p=\frac{1}{16}

\mathrm{Hope\:This\:Helps!!!}

\mathrm{-\:austint1414}

8 0
2 years ago
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