To solve equations such as the ones you listed above, our end goal is to isolate the variable (the letter that represents an unknown value).
Let’s begin with Number 15.
a/5 - 2 = 9
Due to the reverse order of operations, we should first add 2 to both sides of the equation.
a/5 = 11
To solve, we should multiply both sides by 5 to get rid of the denominator on the variable a.
a = 55 (answer)
Next, we can move onto number 18.
2/3g + 6 = -12
To solve this equation, we should begin by subtracting 6 from both sides.
2/3g = -18
Next, we can get the variable g alone by multiplying both sides by 3/2 (this will cancel out the coefficient of 2/3 on the variable g).
g = -27 (answer)
Finally, we can solve number 21 in a similar manner.
(c-5)/4 = 3
To solve this problem, we should first multiply both sides by 4 to get rid of the denominator on the variable c.
c - 5 = 12
To finish our simplification, we should add 5 to both sides of the equation to get the variable c completely alone.
c = 17 (answer)
Therefore, your answers to questions 15, 18, and 21, are 55, -27, and 17, respectively.
Hope this helps!
