By expanding $\left(b+7\right)^2$(b+7)2, we want to determine the factorisation for $b^2+14b+49$b2+14b+49.
First expand $\left(b+7\right)^2$(b+7)2.
Hence, factorise $b^2+14b+49$b2+14b+49.
By expanding $\left(y-5\right)^2$(y−5)2, we want to determine the factorisation for $y^2-10y+25$y2−10y+25.
Factorise $x^2+10x+25$x2+10x+25
Factorise $x^2+14x+49$x2+14x+49