# Hello! Please, tell me which method solving this equation (17 = 10 -x + 2) is correct:a) 17 = 10 -x +2 17 = 12 -x / -12 5 = -x /: -1 -5 = xb) 17 = 10 -x +2 /-2 15 = 8 -x...

Hello!

Please, tell me which method solving this equation (17 = 10 -x + 2) is correct:

a)

17 = 10 -x +2

17 = 12 -x / -12

5 = -x /: -1** -5 = x**b)

17 = 10 -x +2 /-2

15 = 8 -x /-8

7 = -x /:-1

**-7 = x**

Thanks in advance,

Alexander.

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### 6 Answers

Option A is correct.

17 = 10-x+2 = 12-x

or, x = 12-17 = -5.

An easy way to figure out the right approach is to substitute the answer into the original equation and verify if it satisfies the equation.

If approach A is correct, then x = -5 should satisfy the equation,

i.e. 17 = 10-(-5)+2 = 10 +5+2 = 17.

since LHS = RHS, therefore x=-5 is an answer.

If option B were correct, then x = -7 should satisfy the equation

i.e., 17 = 10-(-7)+2 = 10+7+2 = 19.

here LHS is not equal to RHS, thus x=-7 is not a solution. Hence approach B does not work.

Therefore, option A is correct and provides the right answer.

Hope it helps.

This question requires algebra. To simplify this equation, you first need to add 2 and 10. This means that 17 equals to 12 -x. Next you need to take 12 on the left hand side and subtract it from 17 as side change means sign change. Now 5 equals to -x and x will be equal to 5. This shows that option A is correct.

17=10-x+2

17=10+2 -x

17= 12 -x

17-12= -x

5= -x

x =-5

Hope it helps!

### User Comments

**a) **Is correct.

Instead of looking at how both of these choices work, you can instead just do the algebra yourself to see which one of the answers has the value of x that you solved for. So, doing the algebra,

[See attached image for full explanation]

Hope I helped!

17=10-x+2

=> 17=12-x

=> 17-12= -x

=> 5= -x

=> x =-5

So,**option a** is the answer

Option A is the correct option.

you can check this by substituting -5 back into the original equation

A