Jun
2017
Math 9 Final Review 2017
I chose to review the solving equations unit.
The equation I’m going to be solving is: -0.11(3a+5) = 0.37(2a-1)
Step 1 to solving this equation -0.11•3a = -0.33a 0.37•2a = 0.74a
is to distribute the number outside -0.11•5 = -0.55 0.37•-1 = -0.37
the parenthesis to the numbers inside
Step 2, once you have your equation -0.33a-0.55 = 0.74a-0.37
rewritten you need to isolate the variable. +0.37 +0.37
To do this I started by adding +0.37 on both sides . = o.18
Now I’m left with the equation -0.33a+0.18 = 0.74a
Next I added -0.33a on both sides +0.33a +0.33a
I’m left with +0.18 = 1.07a as my new equation
Step 3 is to divide 1.07a on both sides so I’m left 0.18 = 1.07a
with just the variable on the left side and a new ____ ____
number on the left 1.07a 1.07a
My final answer is -0.17=a
After solving an equation it’s important to verify the solution. To verify this, I’m replacing the “a’s” in the equation with -0.17 because that’s what “a” is equal to.
-0.11 [(3•-0.17)+5] = 0.37 [(2•-0.17)-1]
0.056 -0.55 = -0.13 -0.37
-0.494 = -0.5
If both numbers on both sides of the equation sign are equal, then you know that -0.17=a is true.
Once I round -0.494 up to the closest decimal it will be equal to -0.5
Therefore -0.5 =-0.5