[Video] Q1: X-1/3 = k and k = 3, what is the value of x?

Explanation for Question 1 From the Math (No Calc) Section on the Official Sat Practice Test 1

So number one asks us to find the value of X and they give 2 us this equation here. And then they tell us that K is equal to 3 three. And so we know that X minus one, 4 over three is equal to K, right? 5 But we're told that K is equal to three. So let's go ahead and 6 plug that in. Now my goal is to solve for X and if 7 I want to solve for X, the first thing I want to think about 8 removing from the left side of the equation is this three, 9 right? It's in my way, it's attached to the X. 10 And if I have a three in the denominator, it's like, 11 I'm dividing by three. I'm doing X minus one divided by three. 12 So to remove that three, I need to multiply both sides of the equation 13 by three. Because when I multiply these threes, 14 cancel at least new with X minus one and whatever I do to the 15 right I have to do to the left and vice versa. 16 So three times three gives me nine. I can then add one to both 17 sides to get a final answer of X is equal to 10.