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4 years ago

Explain how you would round 33 and 89 to estimate their sum

1 answer:

5 0

If I'm understanding the question correctly, this is how I would estimate the sum.

I would round each number to the nearest tens place.

33 would be rounded down to 30.

89 would be rounded up to 90.

Then I would do 90+30.

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the temperature in Nico's town was -2.9 f at noon . the temperature increased at a steady rate of 1.3 f per hour until 6:00p.m.

kotykmax [81]

Temperature at noon: Tn=-2.9 f
Rate: r=+1.3 f/h
Total decreased: d=-3.7 f
Temperature at midnight: Tm=?

Tm=Tn+r(6 p.m.-12 m)+d
Tm=-2.9 f+(1.3 f/h)(18 h-12 h)+(-3.7 f)
Tm=-2.9 f+(1.3 f/h)(6 h)-3.7 f
Tm=-2.9 f+7.8 f-3.7 f
Tm=1.2 f

Answer: T<span>he temperature at midnight was 1.2 f</span>

6 0

3 years ago

Joel made egg sandwiches and tuna sandwiches in the ratio 2:3. He then made 15 more tuna sandwiches and the ratio changed to 1:3

Aleksandr [31]

Answer:

40 sandwiches

Step-by-step explanation:

egg sandwiches : tuna sandwiches

2 : 3

Multiply by x because we do not know how many sandwiches, just the ratio

2x : 3x

Add 15 tuna sandwiches

2x : 3x+15

Now the ratio is 1:3

egg sandwiches : tuna sandwiches

1 : 3

Multiply by y because we do not know how many sandwiches, just the ratio

y : 3y

Set the number of egg sandwiches equal

2x =y

then set the number of tuna sandwiches equal

3x+15 = 3y

We know have a system of 2 equations and 2 unknowns

Substitute y =2x into the second equation

3x+15 = 3(2x)

Distribute

3x+15 = 6x

Subtract 3x from each side

3x-3x+15 = 6x-3x

15 =3x

Divide by 3

15/3 = 3x/3

5 =x

egg sandwiches : tuna sandwiches

2 : 3

Multiply by x because we do not know how many sandwiches, just the ratio

2x : 3x

2*5 3*5

10 15

He originally made 10 egg sandwiches and 15 tuna sandwiches

Then he made 15 more tuna sandwiches

The total number of sandwiches he made is

10+15+15 = 40 sandwiches

5 0

3 years ago

Simplifying expressions without negative exponents with variales

Olin [163]

Multiply (or distribute) the exponent outside the parenthesis with every exponent inside the parenthesis, remember that if there is no exponent shown, then the exponent is 1. Step 3: Apply the Negative Exponent Rule. Negative exponents in the numerator get moved to the denominator and become positive exponents.

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4 years ago

Initially 100 milligrams of a radioactive substance was present. After 6 hours the mass had decreased by 2%. If the rate of deca

lyudmila [28]

The half-life of the radioactive substance is 67.95 hours.

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2 years ago

E=I(R+r) solve for R

svetlana [45]

Divide I from both sides then subtract r from both sides, too so in the end:

R= (E-r)/I

8 0

3 years ago

Read 2 more answers