Answer:
1x12
2x6
3x4
4x3
6x3
12x1
Step-by-step explanation:
Hi there,
Your question is "twice a number (x) is fifty"
Recall how a number is represented by x.
Twice a number would be represented as 2x.
Therefore, to represent that twice a number is equal to 50, that would result in the expression: 
If you're looking to solve this equation, it's often best to think about the "reverse" of the current equation.
Notice how 2 is multiplying the x.
To isolate x, divide that side by 2.
However, recall that whatever is done to one side of an equation must also be done to the other side of the equation. Therefore, you will need to divide both sides by 2.



Equation: 
Solving for x: 25
Hope that helps!
Z - (-9) is the same as z + 9. Subtracting a negative is the same as adding.
Therefore
17 = z - (-9)
is the same as
17 = z + 9
To get 'z' all by itself, we need to subtract 9 from both sides. We subtract 9 from both sides to undo the "plus 9" occurring to the 'z' on the right side.
17 = z + 9
17-9 = z + 9=9 ... subtracting 9 from both sides
8 = z
z = 8
So the answer is z = 8
---------------------------
Check:
17 = z - (-9)
17 = 8 - (-9) ... replace z with 8
17 = 8 + 9
17 = 17
Answer checks out
So your base equation would be y = 15x - 45
(The -45 is the free three months)
Then you would substitute 90 into the y position and solve, so your answer would be 9 months.
Answer:
Simultaneous equations are two or more algebraic equations that share variables e.g. x and y . They are called simultaneous equations because the equations are solved at the same time. Each of these equations on their own could have infinite possible solutions.