Mathematics for IGCSE & O level - Algebraic Manipulation (Section 6 - No. 11)
Which of these expressions are equivalent?
4x + 3x and 7x
2(x + 1) and 2x + 1
x^2 - 4 and (x-2)(x+2)
a + a + a and 3a
Paliwanag
4x + 3x = 7x; x^2 - 4 = (x-2)(x+2); a + a + a = 3a. 2(x+1) = 2x + 2, not 2x + 1