The answer to 8a. is 17, the answer to 8b. is 3.9, the answer to 8c. is 1 / 2, the answer to 8d. is 7 7 / 8, the answer to 9a. is commutative property, the answer to 9b. is multiplicative identity property, the answer to 9c. is associative property, and the answer to 9d. is additive inverse property.
Regarding the whole "explain using mental math" thing, I pretty much just used the fact that 8a. and 8b. both had the same number of decimal places. For 8c., I just made each number have a denominator of 10. And last, for 8d., all of the denominators were already the same, which made it pretty easy. I apologize for this section of my answer being so informal lol, I haven't had to do these kinds of problems in like 5 years <span />
Answer:
49
Step-by-step explanation:
- Try finding pattern of last two digits of 7 to the power of some numbers.
7^1=07
7^2=49
7^3=343
7^4= 2301
7^5= 16807
- so , the pattern is, 07,49,43,01
- so, if we start writing all numbers from 1 to 2018 , four number in each line, 2018 will fall in the second column.
- so it will have 49 as the last 2 digits [by seeing this pattern : 07,49,43,01 ]
This is how you would set it up
42 47
----- -----
100 x
Then, cross multiply. You should get this:
42x = 4700
Then, solve that problem
42x = 4700
----- -------
42 42
x = 111 < (the answer turns out as a decimal but you should take the whole number)
Then subtract 111 and 100
111 - 100 = 11
Answer - 11%
Hope this helps!
Answer:
16 units²
Step-by-step explanation:
Area of the right triangle = ½ × base × height
base = 8
height = 4
Substitute
Area = ½ × 8 × 4
Area = ½ × 32
Area = 16 units²
Answer:
10in
Step-by-step explanation:
8-3=5
5+5=10