Let 
be the number of liters of the 10% solution to be used, and 
the number of liters of the 4% solution. The chemist wants to end up with a 4 liter solution, so
For each liter used in the mixture, a concentration of either 10% or 4% acid will be contributed, and the goal is to make a 4L solution whose concentration is 7%, which means
Solving for 
gives 
, so 2L of both solutions is needed.
Answer:
The triangles are congruent.
Step-by-step explanation:
Don't let those little lines mess up. Both triangles have the same shape and size. They are congruent.
Answer: mass and the distance apart are the factors that affect the force of gravity
Step-by-step explanation:
To increase the force of gravity on an object, you must increase the mass of the object and decrease the distance between objects.
