b) `37^2 +37. 26+13^2`
`=37^2 + 2.37.13+13^2`
`=(37+13)^2`
`=50^2=2500`
c) `51,7^2-2.51,7.31,7+31,7^2`
`=(51,7-31,7)^2`
`=20^2=400`
d) `(x+3)^3-x(3x+1)^2+(2x+1)(4x^2-2x+1)=38`
`<=>(x+3)^3-x(3x+1)^2+(2x)^3+1^3-38=0`
`<=>x^3+9x^2+27x+27-9x^3-6x^2-x+8x^3-37=0`
`<=>3x^2+26x-10=0`
`<=>x=(-13\pm\sqrt199)/3`