Question

Pls help meeeeeeeeeeeeee

Answer 1

Answer:

the right answer is:

• (A) $2+\frac{1}{2}a$

Step-by-step explanation:

You take the equations that the exercise give you:

1. x + y = 4
2. x - y = a

Now you clear the "y" variable in any equation you want, in this case, I'm gonna use the second equation:

• x - y = a
• -y = a - x

   3. y =  x - a

And now, you'll replace this third equation in the equation you didn't take (the first in this case).

• x + y = 4
• x + (x - a) = 4
• x + x - a = 4

Add the x variables:

• 2x - a = 4
• 2x = 4 + a
• x = (4 + a) / 2

That's the answer of the exercise, but you can represent this in this form:

• x = (4 + a) / 2    ↔  $x = \frac{4}{2} + \frac{1}{2} a$

• x = (4 + a) / 2    ↔  $x = 2+ \frac{1}{2} a$

By this reason, the right answer is $x = 2+ \frac{1}{2} a$.