Question

If y=5x-3(3x+7), what is the value of x when y=-18?

Answer 1

Answer:

x = -3/4

Step-by-step explanation:

Simplify the equation.

5x - 3(3x + 7) = y

5x - 3*3x + 7 *(-3) = y   {Distributive rule}

         5x - 9x - 21 = y  

Combine like terms

           -4x - 21 = y

Now, substitute the value of y = -18

-4x - 21 = -18

Add 21 to both sides

-4x  = -18 + 21

 -4x = 3

Divide both sides by -4

x = -3/4