Respuesta :

Answer:

The value of x is -12

The value of a is -3/4

Step-by-step explanation:

4.)

-3x - 15 = 21

add 15 both side we get,

-3x - 15 + 15 = 21 + 15

-3x = 36

3x = -36

Now, divide both side by 3 we get,

3x/3 = -36

x = -12

Thus, The value of x is -12

5.)

-3(a - 7) = 24 + a

-3a + 21 = 24 + a

Now, Subtract 21 from both side we get,

-3a + 21 - 21 = 24 - 21 + a

-3a = 3 + a

Now, Subtract a from both side we get,

-3a - a = 3 + a - a

-4a = 3

4a = -3

Now, divide both side by 4 we get,

4a/4 = -3/4

a = -3/4

Thus, The value of a is -3/4

FOR VERIFICATION ONLY:

4.)

-3x - 15 = 21

-3(-12) - 15 = 21

36 - 15 = 21

21 = 21

5.)

-3(a - 7) = 24 + a

-3(-3/4 - 7) = 24 -3/4

9/4 + 21 = 24 - 3/4

9/4 + 3/4 = 24 - 21

12/4 = 3

3 = 3

Hence, L.H.S = R.H.S

-TheUnknownScientist 72

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