Answer Choices
9/20
4/5
5/4
20/9
Explanation for Question 7 From the Math (Calc) Section on the Official Sat Practice Test 3
Not for number seven, we're asked what is the value of w so what 2 they really want us to do here is to solve for w in step 3 one of doing that really, and this is kind of maybe a tough step 4 to see if it was hard for you to start. This problem is realizing 5 that when they just have the w out here, the w is also in 6 the numerator. So another way I could write this would have been three w 7 five, over five is equal to four thirds. 8 And so now we just have two fractions, right? We, 9 rather than this, this w out here, 10 um, reason being, why you can do this is because that's really three over 11 five times w over one, if you multiply across, 12 you got the three w over five. So if it was hard for you 13 to start that problem, maybe you had trouble with this step. 14 Um, but whenever you see two fractions set equal to each other, 15 and you're trying to solve for something within those fractions, 16 like a w you first want to cross multiply, 17 that'll always be the case, right? So three times three w gives me a 18 nine w and five times four gives me a 20. 19 And so to solve for w here, I need to divide by nine, 20 that way these nines cancel. And that leaves me with a w is equal 21 to 20 over nine, which we see here in answer choice D.