Is it possible to solve question 3 of Solving systems of linear equations using the solving for expressions method? If so, how do you do it?

# The Math Guide is (basically) back in stock at Amazon

At long last, and just in time for the summer prep rush, the Math Guide is back to showing “usually ships in 1-2 days” at Amazon. (UPDATE 5/30/2020: now it’s all the way back in stock!) I still don’t have stock to ship myself, so if you want a physical book you have to go (more…)

# Test 10 section 4 number 28

Test 10 section 4 number 28

# #19 (no calculator) from test 10

#19 (no calculator) from test 10

# #20 (no calculator) from test 10

#20 (no calculator) from test 10

# How do you do Test 9 section 3 number 20?

How do you do Test 9 section 3 number 20?

# test 9 section 3 number 18

test 9 section 3 number 18

# Amazon says it will take 10 days to ship me your book!

Amazon says it will take 10 days to ship me your book!

# Extending 3-month Math Guide Online subscriptions

In light of yesterday’s announcement by the College Board that the June SAT is canceled, I am extending all current 3-month subscriptions to the Math Guide Online through August 29 (the date of the August SAT). New 3-month subscriptions purchased between now and May 29 will also be extended through the August date. Stay safe (more…)

# Try the Math Guide Online for free

UPDATE: Now you can sign up for trial access (3 days) to the whole Math Guide Online. A bunch of folks have asked me if there’s a free trial for the new Math Guide Online. Well, at launch there wasn’t but now there is! Click above. If you’re ready to purchase access to the whole (more…)

# Available now: SAT Math Guide Online

For the past few months I’ve been working on an online, interactive version of PWN the SAT: Math Guide, and I’m excited to announce that subscriptions are available now in the PWN store!

# The country hall charges a rental fee of $1000 and at least $3000 for food. Olivia is planning a class reunion…

The country hall charges a rental fee of $1000 and at least $3000 for food. Olivia is planning a class reunion. If she had chosen a buffet that costs $38.56 per person what is the minimum possible number of people who must attend to support the expense?

# In a certain class of 70 students, 4/7 of the students are boys, and the ratio of students 10 years or older to students less than 10 years is 2:3. If 2/3 of the girls are less than 10 years old, how many boys are 10 years old or older?

OK, so you have 40 boys and 30 girls. That’s easy enough to calculate because you’re given a part:whole ratio (boys to total students) and you already know the total number of students is 70. Be careful about the second ratio, though, because it’s a part:part ratio! If the ratio of older to younger is (more…)

# The polygon ABCDEFGHI is a regular 9-sided polygon with consecutive vertices labeled in alphabetical order. What is the measure of angle ACE?

OK, so when you have a regular n-gon, you can figure out each angle in it using this formula: [(n-2)180]/n. In this case, 7*180/9 = 140, so we know each angle in the polygon is 140°. I couldn’t draw this quickly on the computer I’m on, so I found a good n-gon picture to mark (more…)

# Thomas is making a sign in the shape of a regular hexagon with 4-inch sides…

Thomas is making a sign in the shape of a regular hexagon with 4-inch sides, which he will cut out from a rectangular sheet of metal. What is the sum of the areas of the four triangles that will be removed from the rectangle?