[Video] Q10: If t+5/t-5 , what is the value of t ?

Explanation for Question 10 From the Math (No Calc) Section on the Official Sat Practice Test 4

I hear a number 10, we're given a fraction, 2 right? T plus five over T minus five, 3 which is equal to 10 and we're told to solve for T. 4 And so your immediate issue is probably while I see Tina numerator, 5 I see Tina denominator. So how do I get them separated? 6 And the answer here is going to be cross, 7 um, multiplication, right? 8 And so the way to do that is first we can set the 10 9 over one so that it makes it a little bit more clear and we're 10 going to multiply the denominator of one fraction times, 11 the numerator of the other and vice versa. 12 So one times T plus five, 13 that's just T plus five, right? And then we have T minus 10 14 times 10, or actually this is 18 minus five. 15 I apologize. Um, 16 times 10. So that's 10 times T minus five. 17 And that process allows me to get rid of the fraction. 18 So what I can do is distribute that 10 to simplify even further, 19 I've got 10 T minus 50 and the solve for T I want to 20 get all my teen numbers to the right side of the equation and all 21 my normal numbers to the left side. So I'll subtract T from 22 both sides here, and that allows a bees to 23 cancel leaving me with five is equal to 90 minus 50. 24 So now I need to move that 50 over to the left side of 25 the equation. I'll do that by adding 50 to both sides. 26 So these cancel and I get 55 is equal to 90. 27 Last thing in my way is that nine that's attached to the T. 28 So I'll divide both sides by nine. 29 That way, those nines cancel. I get that 55 over nine is 30 equal to T which we see in answer choice D.