Resposta:
a) (3g-4j)(3g+4j)
[tex]3 {g}^{2} + 12gj - 12gj + 16 {j}^{2} \\ 3 {g}^{2} + 16 {j}^{2} [/tex]
b) 2(x +5)
[tex]2 \times x + 2 \times 5 \\ 2x + 10[/tex]
c)x(x - 10y)
[tex]x \times x - 10y \times x \\ {x}^{2} - 10xy[/tex]
d)(x+4)(x+4)
[tex]x \times x + 4 \times x + 4 \times x + 4 \times 4 \\ {x}^{2} + 8x + 16[/tex]
