If x + y = 2y - x + 1 = 5, find the value of x

Analyze the question: The chain x + y = 2y − x + 1 = 5 means both expressions equal 5, which gives two simultaneous equations.

Set up the equations:

• (1) x + y = 5
• (2) 2y − x + 1 = 5, so 2y − x = 4

Solve by elimination: Add equations (1) and (2) so that x cancels:

(x + y) + (2y − x) = 5 + 4 3y = 9 y = 3

Substitute back into (1): x + 3 = 5 x = 2

Check in the second expression: 2(3) − 2 + 1 = 6 − 2 + 1 = 5 ✓

So x = 2, which is option B.

Tip: When you see a chain like "A = B = C", split it into separate equations (A = C and B = C). Then use elimination when the coefficients of one variable are opposites, as with +x and −x here, since adding the equations removes that variable immediately.