Question

5x- 2y = 30
Complete the missing value in the solution to the equation.
(8,____)

Answer 1

The missing value is 5.

Explanation:

Since we already have x-value for the equation. What we need to do is to substitute the value of x in the equation.

Substitution

`5x - 2y = 30`

Then we substitute x = 8 in the equation.

`5(8) - 2y = 30 \\ 40 - 2y = 30 \\ 40 - 30 = 2y \\ 10 = 2y \\ (10)/(2) = y \\ 5 = y`

Answer Check

It is better to check the answer before jumping to the conclusion. We can check if the answer is right by substituting both terms in the equation. If the equation is true then the answer is correct. If the equation is false then one of the term is incorrect.

`5x - 2y = 30`

Substitute x = 8 and y = 5 in the equation.

`5(8) - 2(5) = 30 \\ 40 - 10 = 30 \\ 30 = 30`

The equation is true for (8,5)

Therefore, the missing value is 5.