Question

4) – (IEZZI) Determine x e y.

Answer 1

Explicação passo-a-passo:

Utilizando base média:

• $\sf y=\dfrac{4+16}{2}$

$\sf y=\dfrac{20}{2}$

$\sf \red{y=10}$

Seja z base média entre x e y

Temos que:

• $\sf z=\dfrac{x+y}{2}$

$\sf z=\dfrac{x+10}{2}$

$\sf 2z=x+10$

$\sf z=\dfrac{x+10}{2}$

• $\sf x=\dfrac{4+z}{2}$

$\sf 2x=4+z$

Substituindo z por $\sf \dfrac{x+10}{2}$:

$\sf 2x=4+\dfrac{x+10}{2}$

$\sf 2\cdot2x=2\cdot4+x+10$

$\sf 4x=8+x+10$

$\sf 4x-x=8+10$

$\sf 3x=18$

$\sf x=\dfrac{18}{3}$

$\sf \red{x=6}$