HELP! refer to photo

Calcula la concentracion de hidronio en la lluvia ácida si el ph es 4.35

Question 12 of 252 pointssteps for solving 6x- 18 = 54 are shown.explain how step 1 solve the equation.6x -18 = 546x -18 +18 = 54 +186x = 72original equationstep 1step 2step 36x 7266x = 12step 4.oa. adding 18 to both sides isolates the variable.des sb. subtracting 18 from both sides undoes the subtraction.oc. adding 18 to both sides isolates the variable term.od. subtracting 18 from both sides combines like terms.

Julio trabajó como periodista durante mucho tiempo; muy famoso. a. era b. eran c. es d. éramos