ax + ay + bx + by = a(x + y) + b(x + y) = (a + b)(x + y)1 - bx - x + b = (1 - x)(1 - b)ab - a + 2a - 2b = a(b - 1) + 2(a - b) = a(b - 1) - 2(b - a)x + xy + ax + ay = x(1 + y) + a(x + y) = x(1 + y) + a(x + y)
ax + ay + bx + by = a(x + y) + b(x + y) = (a + b)(x + y)
1 - bx - x + b = (1 - x)(1 - b)
ab - a + 2a - 2b = a(b - 1) + 2(a - b) = a(b - 1) - 2(b - a)
x + xy + ax + ay = x(1 + y) + a(x + y) = x(1 + y) + a(x + y)