Let's build the equation counting how many x's and 1's are there on each side.
On the left hand side we have 5x's and 8 1's, for a total of 
On the left hand side we have 3x's and 10 1's, for a total of 
So, the equation we want to solve is

Subtract 3x from both sides:

Subtract 8 from both sides:

Divide both sides by 2:

Answer:
Step-by-step explanation:
u had 11 and u spent 7
7/11 <=== the fraction of money u spent is 7 out of 11
Easy
when rock is in water, it takes up a certain volume, say x
so
initial+x=final volume
luckily we have final and inital
13.7ml+x=28.9ml
minus 13.7ml both sides
x=15.2ml
the volme of the rock is 15.2ml
Answer:
−3x+4
Step-by-step explanation: