Solve systems of equations by algebraically x-2y=7
2x+5y =5

(5,-1) or x=5 y=-1

Step-by-step explanation:

I used the substitution method to solve this!

1. Pick one of your equations and solve for one of the variables. I chose the first equation and solved for x.

x-2y=7

(Move the -2y to the other side of the equation in order to get the x by itself. You do the opposite, so it becomes +2y.)

x=2y+7

2. Now take your second equation and plug in what you got for x into the x variable.

2(2y+7)+5y=5

(Multiple 2 by everything inside of the parentheses.)

4y+14+5y=5

(We want to get the y by itself, so move the 14 to the other side.)

4y+5y=-14+5

(Combine all the like terms.)

9y=-9

(Divide the 9 from the y. What you do to one side you must do to the other.)

y=-1

3. Since you have one variable solved for. Now take the first equation and plug in your y.

x-2(-1)=7

(Multiple -2 by -1)

x+2=7

(Move the 2 to the other side in order to get the x by itself.)

x=5

4. If needed, plug in your x and y values into the equations in order to check your answer.

Hope this could help!

constant of proportionality = 3 and the equation is c = 3p.

step-by-step explanation:

c = kp   where c = amount of caffeine in mg., p = oz of pepsi and k is the constant of proportionality.

substituting the values given:

24 = 8k

k = 3.

the same value of k will be obtained if we substitute the other given values.