Question

a) x2 - 3y, para x = 4 e y= 7​

Answer 1

Bom Dia !!!

$x^2 - 3y\\\\Trocamos\ x\ por\4\ e\ y\ por\ 7:\\\\(4)^2 - 3.(7)\\\\16 - 21\\\\{\boxed{\sf Resultado = - 5}$

Espero ter ajudado :-)

Att: LDC