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2 years ago

12

Geoff must mentally multiply –5 × 0.75 × 20. Which shows how Geoff could use the associative and commutative properties to make

this product easier to find? A –5 ×75100× 20 B (–5 × 20) × 0.75 C 20 × (0.75 × (–5)) D –5 × (20 × 0.75)

2 answers:

joja [24]2 years ago

4 0

Answer:

Step-by-step explanation:

–5 × 0.75 × 20 could be rewritten (applying the associative property) as –5 × (0.75 × 20). I chose this configuration because 0.75 * 20 is 15. Next, evaluate -5(15). This is -75. This matches Answer D.

katrin [286]2 years ago

3 0

Answer:

The Answer is B.

Step-by-step explanation:

The guy above be was wrong. I put D, and it was incorrect. So...

The answer is B!

You're welcome!

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A luxury chairs manager found that an employee made 3/4 of a chair every 3/8 of an hour

ella [17]

Answer:

Step-by-step explanation:

(3c/4)/(3h/8)

(3c/4)(8/3h)

(24/12)c/h

2 c/h

So employee can make 2 chairs in one hour.

7 0

2 years ago

What is the surface area of a rectangular prism that has a height of 5 cm, a width of 10 cm, and a depth of 4 cm?

Ket [755]

Option C: $220 \ cm^2$ is the surface area of the rectangular prism

Explanation:

The height of the rectangular prism is 5 cm

The width of the rectangular prism is 10 cm

The depth of the rectangular prism is 4 cm

We need to determine the surface area of the rectangular prism.

The surface area of the rectangular prism can be determined using the formula,

$A=2(w l+h l+h w)$

Substituting $w=10$ , $h=5$ and $l=4$ in the formula, we get,

$A=2 \cdot(10 \cdot 4+5 \cdot 4+5 \cdot 10)$

Multiplying the terms within the bracket, we have,

$A=2 \cdot(40 +20+5 0)$

Adding all the values within the bracket, we get,

$A=2 \cdot(110)$

Multiplying, we have,

$A=220$

Thus, the surface area of the rectangular prism is $220 \ cm^2$

Hence, Option C is the correct answer.

4 0

3 years ago

Read 2 more answers

Please show work too I really need help

kumpel [21]

Answer:

i really really like ya cut g

Step-by-step explanation:

3 0

3 years ago

Element X is a radioactive isotope such that its mass decreases by 26% every day. If an experiment starts out with 810 grams of

ioda

Answer:

The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.

The function to represent the mass of the sample after t days is $A(t) = 810(0.74)^t$

Step-by-step explanation:

Exponential equation of decay:

The exponential equation for the amount of a substance is given by:

$A(t) = A(0)(1-r)^t$

In which A(0) is the initial amount and r is the decay rate, as a decimal.

Hourly rate of change:

Decreases 26% by day. A day has 24 hours. This means that $A(24) = (1-0.26)A(0) = 0.74A(0)$ ; We use this to find r.

$A(t) = A(0)(1-r)^t$

$0.74A(0) = A(0)(1-r)^{24}$

$(1-r)^{24} = 0.74$

$\sqrt[24]{(1-r)^{24}} = \sqrt[24]{0.74}$

$1 - r = (0.74)^{\frac{1}{24}}$

$1 - r = 0.9875$

$r = 1 - 0.9875 = 0.0125$

The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.

Starts out with 810 grams of Element X

This means that $A(0) = 810$

Element X is a radioactive isotope such that its mass decreases by 26% every day.

This means that we use, for this equation, r = 0.26.

The equation is:

$A(t) = A(0)(1-r)^t$

$A(t) = 810(1 - 0.26)^t$

$A(t) = 810(0.74)^t$

The function to represent the mass of the sample after t days is $A(t) = 810(0.74)^t$

5 0

3 years ago

Find what x is? 5×3>4+8+x a good help for your brain!

MaRussiya [10]

Answer:

x = 2.25 or any number greater

Step-by-step explanation:

5x3 > 4 + 8 + x

Make them equal to each other to get x

5x3 = 4 + 8 + x

(5x)(3) = 12 + x

- x - 3 - 3 - x

4x = 9

$\frac{4x}{4} = \frac{9}{4}$

x = 2.25

Once you get x plug it in to get the truth of the expression

6 0

3 years ago