Distribute the 5 to each of the numbers so you should get 5x+5+5x+5+5x+35. after this you should combine like terms, all of the 5’s & the 35 and 5x’s. you should have 15x+45. then you divide 45 by the 15 and you should get x=3
To prime factorization would be A: 2 X 3 X 5 X 7
Because if your do 2 X 3 it would be 6
Then you do 5 X 7 it would be 35
And 6 X 35 would be 210
AND THAT IS FACTORING THE PROBLEM
If a single board measures 1/12 of a meter then it would take 12 boards to make a meter. Since, the stack is 2 meters high. You would multiply 12 and 2 to get 24. There is 24 boards in the stack.
I used the quadratic formula and got x= 4, -6