She would need about 6 bags because 7*3=21 6+3=18 so about 6 bags
First you would need to combine like terms. do you know how to do that?
Answer:
see explanation
Step-by-step explanation:
Given the 2 equations
5x + y = 21 → (1)
x - 3y = 9 → (2)
Multiply (1) by 3 and add the result to (2) to eliminate y term
15x + 3y = 63 → (3)
Add (2) and (3) term by term
(x + 15x) + )- 3y + 3y) = (9 + 63)
16x = 72 ( divide both sides by 16 )
x = 4.5
Substitute x = 4.5 into (1) for corresponding value of y
22.5 + y = 21 ( subtract 22.5 from both sides )
y = - 1.5
Solution is (4.5, - 1.5 )
Answer:
1 3/7 quarts should be drained off and replaced with pure antifreeze.
1 3/7 ≈ 1.4286
Current amount of antifreeze in quarts is -
30/ 100 × 10 = 3
40% ---> 4 quarts
Let the amount drained of and replaced with antifreeze be x-
The amount left after draining off is 10 − x.
The amount of antifreeze is 30/ 100 (10−x).
30/100(10-x)+x=4
3-3/10x+x=4
3+x(1-3/10)=4
x=1*10/7=1 3/7 quarts
check;
10- 1 3/7 = 8 4/7
=(30/100*8 4/7)+1 3/7
=(3/10 * 60/7) + 10/7
=3*6/7 + 10/7
=28/7
=4
4 liters of pure antifreeze is mixed into 10 quarts.
Independent variable: the variable that affects the dependent variable and creates a change
Dependent variable: depends on the independent variable
1. Independent variable: John’s age
Dependent variable: height
2. Independent: gallons of milk
Dependent: cups of milk
3. Independent: population
Dependent: number of representatives
4. Independent: Number of seats
Dependent: amount of tickets
5. Independent: time
Dependent: plane’s altitude
6. Independent: more music download
Dependent: more money spent
