Respuesta :

Answer:

0.5

Step-by-step explanation:

20x+90=100

20x=10

x=0.5

Answer: x=0.5

Step-by-step explanation:

20x+90=100

20x+90-90=100- 90

subtract 90 from both sides

20x=10

20x^2=10

20x^2=10

----------------

20         20

divide both sides by 20

x^2=1/2