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3 years ago

Can someone help me and tell me what I got wrong

Mathematics

2 answers:

aliina [53]3 years ago

6 0

I'm not sure what you did at first, but here's how I solved it:

7(3+3)-9

7(6)-9

42-9

=33

i can't see your original answer, so i can't tell you specifically what went wrong, but i hope that helps!

ira [324]3 years ago

4 0

Answer: 33

Step-by-step explanation:

f(a)=7(a+3)-9

f(3)=7(3+3)-9

f(3)=7(6)-9

f(3)=42-9

f(3)=33

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0.27=_ hundredths<br><br>please help me

Alexeev081 [22]

Answer:

27 hundredths

Step-by-step explanation:

.2 is in the tenths place,

.07 is in the hundredth place,

.27 is 27 hundredths

4 0

3 years ago

Read 2 more answers

How many times larger is 3×108 than 3×102?

Vinvika [58]

Answer: 120

Step-by-step explanation:

3 x 108 = 324

3 x 102 = 204

so 324 - 204 = 120

4 0

3 years ago

Two mechanics worked on a car. the first mechanic worked for 10 hours, and the second mechanic worked for 15 hours. together the

Yuliya22 [10]

Let x and y be the rate per hour for Mechanic 1 and 2 respectively.

Then,
x+y=205 ---------- (1)
Additionally,
10x+15y = 2500 ------ (2)

Solving equations 1 and 2;
Multiply (1) by 10 and subtract two from the result,
10x+10y = 2050
10x +15 y =2500
----------------------
-5 y = --450 => y = 450/5 = $90
Then,
x= 205-90 = $115

Therefore,
Mechanic 1 charged $115 per hour
Mechanic 2 charged $90 per hour

3 0

3 years ago

A series of three? separate, adjacent tunnels is constructed through a mountain. Its length is approximately 25 kilometers. Each

Nadya [2.5K]

Answer:

$312.5\pi \text{ km}^3\approx 981.75\text{ km}^3$

Step-by-step explanation:

We have been given that a series of 3 separate, adjacent tunnels is constructed through a mountain. Its length is approximately 25 kilometers.

Each of the three tunnels is shaped like a half-cylinder with a radius of 5 meters.

Since we know that volume of a semicircular or a half cylinder is half the volume of a circular cylinder.

$\text{Volume of a semicircular cylinder}=\frac{\pi r^2h}{2}$ , where,

r = Radius of cylinder,

h = height of the cylinder.

Upon substituting our given values in volume formula we will get,

$\text{Volume of a semicircular cylinder}=\frac{\pi (5\text{ km})^2*25\text{ km}}{2}$

$\text{Volume of a semicircular cylinder}=\frac{\pi*25\text{ km}^2*25\text{ km}}{2}$

$\text{Volume of a semicircular cylinder}=\frac{\pi*625\text{ km}^3}{2}$

$\text{Volume of a semicircular cylinder}=\pi*312.5\text{ km}^3$

$\text{Volume of a semicircular cylinder}=981.74770\text{ km}^3$

Therefore, the volume of earth removed to build the three tunnels is $312.5\pi \text{ km}^3\approx 981.75\text{ km}^3$ .

4 0

3 years ago

Expand and combine like terms.<br> (7b^5 – b^2)^2

KiRa [710]

I got 49b^10-14b^7+b^4

7 0

3 years ago