What is the appropriate indefinite for the word libretas

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.

Which verb form best completes this sentence? pablo picasso el estilo de cubismo. a. invente b. inventaste c. inventó d. invento

La fábrica ha estado tirando ese desecho industrial muchos años en el río. a. para b. por c. por ahora d. para entonces