Question

If 7x+2y=3 and x-3y=30. What is value of Y Please show work

Answer 1

Answer:

The value of Y is - 9.

Step-by-step explanation:

1. Let's start with the first equation to find out the value of Y.

7x + 2y = 3

2y = 3 - 7x

y = 3/2 - 3 1/2x

2. Now let's work with the second equation to find out the value of Y.

x - 3y = 30

x - 3 (3/2 - 3 1/2x) = 30

x - 9/2 + 21/2 x = 30

x + 21/2 x = 30 + 9/2

2x + 21x = 60 + 9

23x = 69

x =  69/23

x = 3

3. Now let's substitute the value of X in the first equation, to find out the value of Y.

7 (3) + 2y = 3

21 + 2y = 3

2y = 3 - 21

2y = -18

y = - 9

4. Proof of the values of X and Y on the second equation

x - 3y = 30 (x = 3 and y = -9)

3 - 3 (-9) = 30

3 + 27 = 30

30 = 30 This means that the values of x and y are correct.