The sister is 4<em>n</em><em> </em>yrs old.
That is because 4 times <em>n</em><em> </em>is 4<em>n</em><em>.</em>
1)
, 2) 
3)
, 4) 
5)
, 6) 
7)
, 8) 
9)
, 10) 
11)
12) 
Step-by-step explanation:
We need to solve each equation.
1) 
Solving:
Adding like terms:

Divide both sides by 11

2) 
Solving:
Adding like terms:

Divide by -8

3) 
Solving:
Adding like terms:

Subtract 9 on both sides:


Divide both sides by 4

4) 
Solving:

Divide both side by -7

5) 
Solving:
12r-1=11
Adding 1 on both sides

Divide both sides by 12

6) 
Solving:

7) 
Solving

8) 
Solving:

9) 
Solving:

10) 
Solving:

11) 
Solving:

12) 
Solving:

Keywords: Solving Polynomials
Learn more about solving Polynomials at:
#learnwithBrainly
Plug in 2 for x, and -4 for y
2(2)² + 3(2)(-4) - (-4)²
2² = 4(2) = 8
3(2) = 6(-4) = -24
-4² = 16
8 - 24 - 16 = answer
Simplify.
answer = 8 - 40
answer = -32
-32 is your answer
hope this helps
Answer:
Step-by-step explanation:
Write the equation as:
Price of books times number of books + price of binders times number of binders = total price
So then the final answer is 3(2)+5(x)=16
Answer:
26.25 mm
Step-by-step explanation:
On the blueprint of a house, 42 millimeters represents 8 meters. Thus,
42 mm - 8 m,
x mm - 5 m,
mathematically,
