Answer:
10 
Step-by-step explanation:
Hi there, hope you are having a nice day!
All we should do is plug in the value of b:
12-2
10 (Answer)
Hope you find it helpful.
Feel free to ask if you have any questions.
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To evaluate this expression, we need to remember that subtracting a negative number is the same as adding a positive number, and that adding a negative number is the same as subtracting a positive number. Using this knowledge, let's begin to simplify the expression below:
-1 - 3 - (-9) + (-5)
Because addition of a negative number is the same as subtraction of a positive number, we can change + (-5) to -5, as shown below:
-1 - 3 - (-9) - 5
Next, because we know that subtracting a negative number is the same as adding a positive number, we can change - (-9) to + 9, as shown below:
-1 - 3 + 9 - 5
Now, we can subtract the first two terms and begin to evaluate our expression:
-4 + 9 - 5
Next, we can add the first two numbers of the expression:
5 - 5
Now, we can subtract our last two numbers, which gives us our answer:
0
Therefore, your answer is 0.
Hope this helps!
Answer:
x = 45/17
Step-by-step explanation:
We can move all x to 1 side and all the numbers to another. You can add 8.7 on both sides and get that 2.3x = 0.8x + 4.5. Next, we subtract by 0.8x on both sides to get that 1.7x = 4.5, where we can then divide by 17/10 on both sides to get that x is equal to 45/10 * 10/17, so that means that x = 45/17.
Using linear combination method to solve the system of equations 3x - 8y = 7 and x + 2y = -7 is (x, y) = (-3, -2)
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Solution:</u></h3>
Given that, a system of equations are:
3x – 8y = 7 ⇒ (1) and x + 2y = - 7 ⇒ (2)
We have to solve the system of equations using linear combination method and find their solution.
Linear combination is the process of adding two algebraic equations so that one of the variables is eliminated. Addition or subtraction can be used to perform a linear combination.
Now, let us multiply equation (2) with 4 so that y coefficients will be equal numerically.
4x + 8y = -28 ⇒ (3)
Now, add (1) and (3)
3x – 8y = 7
4x + 8y = - 28
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7x + 0 = - 21
7x = -21
x = - 3
Now, substitute "x" value in (2)
(2) ⇒ -3 + 2y = - 7
2y = 3 – 7
2y = - 4
y = -2
Hence, the solution for the given two system of equations is (-3, -2)