Which of the following is a solution of the system 2x + y = 9 and 3x + 5y = 19.​

2x+y=9

3x+5y=19

I will do this problem in 2 ways. I.)Substitution II.)Elimination

Solution I.) Substitution

We can subtract 2x from both sides in the first equation.

y=9-2x

Now we can substitute the y in the second equation with 9-2x

3x+5(9-2x)=19

-7x+45=19

-7x=-26

x=26/7

y=9-2(26/7)=11/7

Solution II.)Elimination

We can multiply both side of first equation by 5 to get a 5y in both equations.

10x+5y=45

Now because both are positive 5y we just need to do simple subtraction of the 2 equation, each side respectively.

(10x+5y)-(3x+5y)=45-19

7x=26

x=26/7

2*26/7+y=9

y=11/7

Ultimately you get the same answer, both are viable methods, some problems are faster with one method but I recommend mastering both since they are very useful.

answer: the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

step-by-step explanation:

the given rate of interest i= 85%

in calculating the monthly payment for a loan with an interest rate compounded monthly, the value of the interest rate per period we use in the formula must be in decimal form.

to convert it in decimal, we divide it by 100, we get

hence, the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

arrange the equations with like terms in columns.

analyze the coefficients of x or y.

add the equations and solve for the remaining variable.

substitute the value into either equation and solve.

check the solution.

step-by-step explanation: