Question

3- NA EQUAÇÃO: X + 3X – 20 = 2X + 10, QUAL O VALOR DE X?

Answer 1

$\sf x+3x-20=2x+10\\\\\\4x-20=2x+10\\\\\\4x-20+20=2x+10+20\\\\\\4x=2x+30\\\\\\4x-2x=2x+30-2x\\\\\\2x=30\\\\\\\dfrac{2x}{2}=\dfrac{30}{2}\\\\\\\to \boxed{\sf x=15}$

Answer 2

$\sf Veja\:Abaixo$

Fazemos os cálculos:

$\boxed{\begin{array}{lr} \large \sf x+3x-20=2x+10 \\ \\ \large \sf 4x-2x=10+20 \\ \\ \large \sf 2x=30 \\ \\ \large \sf x=\dfrac{30}{2}\\ \\ \large \sf x=15 \end{array}}$

$\to \large\boxed{\sf x=15}$

Bons estudos =)