Answer:
D. There is no mistake.
Step-by-step explanation:
The following lines show the process of factorization by using common factor.
<u>Line 1:</u>
In line 1, the equation is given and is completely fine.

The only thing missing was equate to zero, but the options below talk about correct factors only, therefore this can't be considered as a mistake and can be ignored completely.
<u>Line 2:</u>
In line 2, the terms are grouped, from which we can factor out common terms.

This is also fine.
<u>Line 3:</u>
In line 3, the common term y is taken out from group 1 and 2 from other group.

which is exactly what is given in line 3.
<u>Line 4:</u>
In line 4 the common factors can be seen and easily split into 2 factors.

which is exactly what is given in line 4.
Options:
A. The grouping is correct in line 2. So this option is does not hold.
B. Common factor was factored correctly from group 1. So this option does not hold.
C. Common factor was factored correctly from group 2. So this option does not hold.
D. There is no mistake. This is correct. Thus we choose this option as correct answer.
Answer: There are 19 classes
Step-by-step explanation:
divide the total amount amount of students by the amount of students in each class
Answer:
A. 4·10⁴
Step-by-step explanation:
The problem statement tells you ...
6×10⁵ miles = 15 × (last year's mileage)
Dividing by 15 gives ...
(60×10⁴ miles)/15 = (last year's mileage) = 4×10⁴ miles
_____
<em>Further explanation</em>
An exponent is an indication of repeated multiplication.
10⁵ = 10·10·10·10·10 = 100,000
We can use the associative property of multiplication to rewrite the number of miles:
6×10⁵ = 6·(10·10·10·10·10) = 600,000 = (6·10)·(10·10·10·10) = 60×10⁴
Answer:
d=0.031746
Step-by-step explanation:
1. Add 4d to both sides: 3.2=2.3d+3+4d
2. Simplify 2.3d +3+ 4d to 6.3d+3: 3.2=6.3d+3
3. Subtract 3 from both sides: 3.2-3=6.3d
4. Simplify 3.2-3 to 0.2: 0.2-6.3d
5. Divide both sides by 6.3: 0.2/6.3=d
6. Simplify 0.2/6.3 to 0.031746: 0.031746=d
7. Switch sides: d=0.031746
Hope this helped!