Square of sum: Number of terms

Simplify the expression $(x+y+1)^2$

$x^2+2x+y^2+2y+2xy+1$

$x^2-(x+4)^2=40$

$x=-7$

$(3+\frac{y}{3})^2=(2+y)^2-\frac{8}{9}y^2$

2.5

$7+(x-5)^2=(x+3)(x+3)$

$x=1\frac{16}{23}$

$\frac{\sqrt{2x^2+4xy+2y^2+(x+y)^2}}{(x+y)}=$

$\sqrt{3}$

Find a a given that

$2a(a-5)=(a+3)^2+(a-3)^2$

$-1.8$

$(7+a)(7+a)=(\frac{1}{2}a+8)^2+\frac{3}{4}a^2$

$a=\text{?}$

$2\frac{1}{2}$

$(8+3x)^2=(5x+3)^2-(4x)^2$

$x=\text{?}$

$-3\frac{1}{18}$

$(5-3a)^2+a=(a+1)^2-31a$

No solution

$(7+xy)^2=3x^2y^2+49$

$\frac{7}{y^2}$