The answer is 30,60,90. Because 60 is twice the number 30 and 90 is three times the first number.
Yo creo que es 1,504.5 gramos en total que compro María!!
The last terms must multiply to the last terms (confusing)
example
if ax^3+bx^2+c+d=(ex+f)(gx+h)(jx+k) then
d=fhk
so
70 is last term
we got 2 and 5
2*5*?=70
10*?=70
divide by 10
?=7
the missing number is 7