Answer:
- 10.2n - 1
Step-by-step explanation:
You need to add the expressions:
- 2.4n - 3 + (- 7.8n +2)
- 2.4n - 3 - 7.8n + 2
- 10.2n -1
We are given
piggy bank has nickels , dimes and quarters
Let's assume
number of nickels =n
every two nickels there are 3 dimes
so, number of dimes are


every two dimes that are 5 quarters there
so, number of quarters are


so, total number of coins = number of nickels + number of dimes +number of quarters
total number of coins =n+1.5n+3.75
there are 500 coins
so, we get

now, we can solve for n

divide both sides by 6.25
so, we get

number of dimes is 1.5n


number of quarters is 3.75n


so,
Number of nickels =80
Number of dimes =120
Number of quarters =300............Answer
X+9x=3
10x=3
The answer is x=3/10
Answer:
I think it’s d
Step-by-step explanation:
Answer:
(5a - [2b - 7c]) and (5a + [2b + 7c])
Step-by-step explanation:
Factor 25a^2 - 4b^2 + 28bc - 49c^2.
Note that - 4b^2 + 28bc - 49c^2 involves the variables b and c, whereas 25a^2 has only one variable. Thus, try to rewrite - 4b^2 + 28bc - 49c^2 as the square of a binomial:
- 4b^2 + 28bc - 49c^2 = -(4b^2 - 28bc + 49c^2), or
-(2b - 7c)^2.
Thus, the original 25a^2 - 4b^2 + 28bc - 49c^2 looks like:
[5a]^2 - [2b - 7c]^2
Recall that a^2 - b^2 is a special product, the product of (a + b) and (a - b). Applying this pattern to the problem at hand, we conclude:
Thus, [5a]^2 - [2b - 7c]^2 has the factors (5a - [2b - 7c]) and (5a + [2b + 7c])