Answer:
- A. 3(10÷2) +2·7
- A. 0.4
- B. -2.8
- C. n·6 - 12 = 60
Step-by-step explanation:
1. The given expression evaluates to ...
30÷2 + 2·7 = 15 + 14 = 29
The offered choices evaluate to ...
A: 3(10÷2) + 2·7 = 3·5 + 2·7 = 15 + 14 = 29 . . . . . this will make it true
B: 30÷(6+2)·7 = (30/8)·7 = 210/8 = 26 1/4 . . . . . . ≠ 29
C: 3(10)÷(2+2)·7 = 30/4·7 = 210/4 = 52 1/2 . . . . . ≠ 29
D: (5+2)·7 = 7·7 = 49 . . . . . . . . . . . . . . . . . . . . . . . ≠ 29
2. You can divide the equation by 10 to find the appropriate value of x.
4/10 = 10x/10 = x . . . . . 4/10 matches choice A
3. The expression simplifies to ...
7.5 -10.3 = -2.8 . . . . . . matches choice B
4. "The product of a number and 6" is n×6. Twelve less is n×6 - 12. When that "is 60", the equation can be written ...
n×6 - 12 = 60 . . . . . . . . matches selection C
Answer:
12
Step-by-step explanation:
144 divided by 2 72
72 by 2 36
36 by 2 18
18 by 2 9
3by 3 3
3 by3 1
2x2 2x2 2x2 3x3
pick on from each set
2x2x3
12
Answer:
Setting up problems like this requires a "system of equations." We'll call the two numbers "A" and "B." Make an equation out of the first sentence. "Sum" means the answer to an addition problem.
A + B = 45
After that, make an equation out of the second sentence. "Difference" means subtraction.
A - B = 3
There are two ways to solve this problem. The two ways are called "elimination" and "substitution." I don't know which way you usually do it, but for this case, elimination is more efficient, so I'll teach you how to do that. Look how "B" is positive in the first equation, but negative in the second equation. If these two equations get added together, the B-terms will cancel.
A + B = 45
A - B = 3
-------------
2A = 48
A = 24
Perfect, we got one of the numbers, which is 24. Plug in A = 24 into any of the equations to find B.
A + B = 45
24 + B = 45
B = 21
This means that our two magic numbers are 24 and 21. The product of these numbers can be found by multiplying them to get 504 (C). I hope this helps, and good luck with the rest of your math class!
As you can see, the area of the scarf is equal to the area of the rectangle minus the area of the 2 semi-circles (which form a circle)
Now, we calculate the area of the rectangle : 28 x 15 = 420 in2
The diameter of the circle is 15in -> The radius = 15 : 2 = 7.5in.
We now find the area of the 2 semi-circles : 7.5 x 7.5 x 3.14 = 176.625 in2
So, the area of the scarf is : 420 - 176.625 = 243.375 in2