iStock
If you know how to use the right formulas, you can pick up a lot of extra points on the ACT Math section by simply filling in the right numbers and calculating the results. (We call this a plug-and-chug question.) Here are some coordinate geometry formulas for slope questions. Check your understanding on these samples and move on to a practice test when you feel ready.
The first thing you need to do with any formula is identify what each variable (or letter) stands for. The name of the formula will often help! In this case, you know the following has something to do with the slope and intercepts (where a line crosses the x-axis and y-axis).
y = mx + b
When the ACT asks you to solve for the slope, y-intercept, or x-intercept, write out this formula. Note that you'll often be given an equation in a different form. In this case, begin by rearranging it into the familiar form above and then solve. Take a look at the example below.
What is the slope of the line 5x – 11y = 7 in the standard (x, y) coordinate plane?
A. –5The question gives you an equation and asks you to find the slope, which tells you it's time to put the slope-intercept formula to use. Start by rearranging your line equation into slope-intercept form, y = mx + b, and paying close attention to any sign changes. The provided line is 5x – 11y = 7, so you'll want to move everything except y to the right of the equal sign.
Step 1: 5x – 11y = 7
Step 2: –11y = –5x + 7
Step 3: y = 5/11x – 7/11
Step 4: The slope, m, is 5/11.
The correct answer is (C).
Always choose the formula that matches the data you're given by the question. While the slope-intercept equation works great when you're given the intercepts, if you are only given two coordinates on a line, you'll need to use the slope formula.
Born and raised in Niagara Falls, Ontario, I was used to small-town living. I attended an international boarding school as a day …
This year’s AP Scores have been released and Trevor Packer, head of the Advanced Placement Program has shared the details of this…
Summer is here, marking one of the best times for motivated high schoolers to enroll in summer programs where they can diversify …
College-level STEM programs are notoriously rigorous, and getting off to a strong start can make a huge difference for students w…
Building a strong personal résumé in your first years of high school is recommended by counselors, college & university admis…
Ascent offers cosigned and non-cosigned student loans with exclusive benefits that set students up for success.
Explore Now!Want to find money for school that doesn’t need to be paid back? Access insights and advice on how to search and apply for scholarships!