Question

Ajuda eu urgente matemática

Answer 1

$i)\\ \\ 10x-81=x+9\\ \\ 10x-x=9+81\\ \\ 9x=90\\ \\ x=\frac{90}{9} \\ \\ x=10\\ \\ j)\\ \\ x+7=-3x+28\\ \\ x+3x=28-7\\ \\ 4x=21\\ \\ x=\frac{21}{4}$

Answer 2

Boa Tarde !!!!

i)10x-81=x+9

10x-x=81+9

9x=90

x=$\frac{90}{9}$

x=10

j)x+7=-3x+28

3x+x=28-7

4x=21

x=$\frac{21}{4}$