what is 5a+30 if it equals 155

Question

i have an substitution grid and i dont know what A will equal if one of the answers equal to 155

Answer 1

5a + 30 = 155

 

To solve for the value of a, you need to get the a by itself on one side of the equation.  Here's how you do it.  First, subtract 30 from both sides of the equation.  Because it's an equation, you need to do the same operations on both sides to keep everything equal.

 

5a + 30 - 30 = 155 - 30                [+30 - 30 = 0]

 

5a = 125

 

Now divide both sides by 5:

 

5a/5 = 125/5                               [5a/5 = a]

 

a = 25

 

Check:

5a + 30 = 155

5(25) + 30 = 125 + 30 = 155    CHECK!