Question

what is the value of y in the equation 5x + 2y =20,when x = 0.3?

Answer 1

   5x + 2y = 20

5(0.3) + 2y = 20

   1.5 + 2y = 20

 - 1.5            - 1.5

            2y = 18.5

             2       2

              y = 9.25

The value of y  is 9.25.

(x, y) = (0.3, 9.25)

Answer 2

First of all, let's plug the value for x:

$5x + 2y =20 \to 5\cdot 0.3+ 2y =20 \to 1.5+ 2y =20$

Now subtract 1.5 from both sides:

$2y = 20-1.5 = 18.5$

Finally, we divide both sides by 2:

$y = \dfrac{18.5}{2}$