When were the National Energy Conservation Awards (NECA)

Simplify:
6x + 8y - [(12x + 6y) - (4x + 3y) + 2y] - 4x

In △ ABC, AB = AC. A circle drawn through B touches AC at D and intersect AB at P. If D is the midpoint of AC and AP = 2.5 cm, then AB is equal to:

If (4x + 3y): (28x - y) = 1: 5, then what is the value of (3x ²  + 4y ² ): (7x ²  + 2y ² )?

If (a + b) = 13 and ab = 18, find the value of (a² + b²).

A train can cross a pole, a bridge of 720 meter long and platform of 640 meter long in 9 seconds, _____ seconds and 25 seconds, respectively.

What is the value of (a² + b²+4c²- ab-2bc-2ca) (a + b+2c):

If x + y = 12 and x² + y² = 74, find xy.

Solve:

x + y = 9

x - y = 3

Find x + 2y.