Question

If you were to solve the following system by substitution, what would be the best variable to folve for and from what equation?

3x+6y=9
2x-10y=13

A) y in the first equation
B) y in the second equation
C) x in the second equation
D) x in the first equation

Answer 1

Answer:

D

Step-by-step explanation:

It's easiest to divide everything by 3.

Answer 2

The best variable to solve for is x in the first equation.

How to solve the equations 3x+6y=9 and 2x-10y=13 by substitution?

Let 3x+6y=9 be equation (1)

and 2x-10y=13 be equation (2)

2x-10y=13

10y = 2x - 13

y =$\frac{2x - 13}{10}$  

substitute the value of y in equation (1)

3x+6y=9

3x + $6(\frac{2x - 13}{10})$ = 9

3x + $3(\frac{2x - 13}{5})$ = 9

$\frac{15x + 6x - 39}{5}$ = 9

21x - 39 = 45

21x = 84

x = $\frac{84}{21}$

x = 4

Therefore, option D) x in the first equation is the correct answer

To learn more about  substitution method, refer :

https://brainly.com/question/22340165

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