Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of

Serena needs 12 grams of the 40% solution and 8 grams of the 70% solution.

Step-by-step explanation:

Let x be the weight of 40% salt solution and y be the weight of 70% salt solution.

We have been given that Serena needs 20 grams of solution of salt. We can represent this information in an equation as:

We are also told that she needs 20 grams of a 52% solution of salt by adding  40% and 70% of salt solutions.

We can represent this information in an equation as:

Now we will use substitution method to solve our system of equations.

From equation (1) we will get,

Substituting this value in equation (2) we will get,

Therefore, Serena must use 8 grams of 70% salt solution.

Upon substituting y=8 in equation (1) we will get,

Therefore, Serena must use 12 grams of 40% salt solution.

answer: c

step-by-step explanation: because you don't have to draw a point of intersection. couldyou give me brainliest?

u

1) c 2143.6 cm

2) c 113.0 m

3) a 33.5 ft

4)   d 2 cm

5) c 20 mm

6) 180 in

7) d 120 ft