49–2ax –a^2–x^2
Extract the negative sign
= 49 - (a^2 +2ax +x^2)
Factor using a^2 + 2ab + b^2 = (a+b)^2
= 49 - (a+x)^2
Factor using a^2 - b^2 = (a-b)(a+b)
= ( 7- (a + x)) * (7 + (a + x))
= ( 7- a - x) * (7 + a + x)