![davidtrott5761](/avatars/44192.jpg)
davidtrott5761
14.05.2021 •
Mathematics
Mr laub has three children
Solved
Show answers
More tips
- F Family and Home How to Build a Strong Relationship with Your Child: Tips for Effective Communication...
- H Health and Medicine Boosting Immunity: A Complete Guide on How to Improve Your Body’s Natural Defenses...
- C Computers and Internet The Best Antivirus Programs for your PC...
- S Style and Beauty How to Get Rid of Acne: Scientifically Proven Methods...
- H Health and Medicine Simple Ways to Lower Cholesterol in the Blood: Tips and Tricks...
- O Other How to Choose the Best Answer to Your Question on The Grand Question ?...
- L Leisure and Entertainment History of International Women s Day: When Did the Celebration of March 8th Begin?...
- S Style and Beauty Intimate Haircut: The Reasons, Popularity, and Risks...
- A Art and Culture When Will Eurovision 2011 Take Place?...
- S Style and Beauty How to Choose the Perfect Hair Straightener?...
Answers on questions: Mathematics
- M Mathematics Choose the correct solution to the equation: 5a+7=3a+7+2a a. no solution b. infinitely many solutions c. none of the above 7b+4=7b-3 a. no solution b. infinitely...
- M Mathematics 8. When working with a set of data you find the mean is 15 and the standard deviation is 3. What does this say about the data relative to the variability. Please...
- M Mathematics In the woods there are 420 silver birch trees, 160 oak trees and 300 wood cherry trees what percentage of the trees are oak trees?...
- E English Which genre exemplifies the way american literature changed in the 20th century? historical fiction science fiction romantic poetry autobiography...
- M Mathematics Minnie has 16 old posters and 25 new posters. amanda has 25 old posters and 16 new posters. who has more posters? explain...
- M Mathematics Students in grade6, 7 and 8 sold a total of 320 concert tickets. grade 6 students sold x tickets grade 7 students sold s tickets and grade 8 students sold t tickets...
Ответ:
He does?
Step-by-step explanation:
Ответ:
Ответ:
Upvote
•
1
Downvote
Add comme
y = -4x
When x = 4, y = -16
When y = 20, x = -5
Step-by-step explanation:
First off, definitions: Direct variations refers to two variables being related with neither being the denominator of a fraction. (nothing along the lines of y = 1/x)
So, given that, I simply found what the ratio was between the two values. Something like buying gas at the gas station. The ratio between the gas you get and the money you pay is the price per gallon of gas. In this case, the proportion is -4 (-16 divided by 4).
Thus we have a relationship. For each y, you have negative four x's. Thus, y = -4x.
Finding the value of x when y = 20 simply requires plugging values in. Remember, a fundamental principle in all of Algebra is substitution. If two things are equal, they are interchangeable. So, if you saw "3 + 4" in a mathematical expression, you could simply erase it and write 7, so long as no other mathematical rules (multiplication before addition, for instance) interferes.
Thus, if y = 20, we can take our original equation and replace y with 20.
y = -4x => 20 = -4x
Then, simply solve for x, keeping in mind that when two items in math are written against each other, it means multiplication. Thus, we reverse the multiplication to division and divide both sides of the equation by -4.
20 / -4 = -5