Question

Given: 8x - 3y = -21, 3x + y = -10; Prove: x = -3

Answer 1

To prove x = -3, you can solve the given system of equations by eliminating y and solving for x.

Step-by-step explanation:

To prove that x = -3, we need to solve the given system of equations:

1. 8x - 3y = -21
2. 3x + y = -10

Step 1: Multiply the second equation by 3 to eliminate y. This gives us:

1. 8x - 3y = -21
2. 9x + 3y = -30

Step 2: Add the two equations together to eliminate y:

17x = -51

Step 3: Divide both sides by 17 to solve for x:

x = -3

Therefore, the value of x that satisfies the given system of equations is -3.

Answer 2

The answer to your question is given below

Step-by-step explanation:

8x – 3y = –21 ..... (1)

3x + y = –10 ...... (2)

To prove that x = – 3

Do the following:

8x – 3y = –21 ..... (1)

3x + y = –10 ...... (2)

Make y the subject in equation 2

3x + y = –10

Rearrange

y = –10 – 3x

Substitute the value of y into equation 1

To get the value of x.

8x – 3y = –21

y = –10 – 3x

8x – 3(–10 – 3x) = –21

Clear bracket

8x + 30 + 9x= –21

Collect like terms

8x + 9x = –21 – 30

17x = –51

Divide both side by 17

x = –51 / 17

x = – 3