Resposta :
Explicação passo-a-passo:
quintuplo de x >>>>>>>>>>>>>>>>>>>5x
dobro de x >>>>>>>>>>>>>>>>>>>> 2x
5x + 2x = 126
( 5 + 2)x = 126
7x = 126
x = 126/7 = 18 >>>>> resposta
Explicação passo-a-passo:
quintuplo de x >>>>>>>>>>>>>>>>>>>5x
dobro de x >>>>>>>>>>>>>>>>>>>> 2x
5x + 2x = 126
( 5 + 2)x = 126
7x = 126
x = 126/7 = 18 >>>>> resposta