120 feet is 2 times as long as 60.
It says that the value of a box above two boxes is found by adding the expressions in the two boxes. I filled in the boxes. The top box is 13x + 30, or option B.
Answer:
You'd have to go step by step to get the actual value of y. Then solve the equations by inputting the value for y, therefore eliminating y from both equations
Total mass = 6.08 x 10^23 * 1.67 x 10^-24 = 1.01536