Algebra???

Question

I homeschool and I have a really bad book that doesn't explain things well. Can anyone help me with these problems?

1. Write a linear equation to model the situation. You borrow $70 from your brother. To repay the loan, you pay him $7 per week. Use w to denote the number of weeks and y as the balance on the loan.

2. Write an equation of the line that passes through the point (3,0) and has the slope, m = -2.

3. Write an equation of the line that is parallel to the given line
y = x + 3 and the given point (5,0).

4. Write an equation in slope-intercept form of the line that passes through the points (-4,2) and (1,-1).

Answer 1

JaNa,
I don't know which curriculum you are using, but I love Saxon. Mr. Saxon designed it using tiny baby steps to learn major concepts. It is especially good for those who are not natural "math people."

I don't want to do your work for you, but I will give you some hints to help you discover the answers for yourself. With algebra, the joy is, there is more than one way to solve a problem. One is only limited by if the instructions direct you to solve it a certain way. So, if you follow the rules, you have several possible choices and you should get the correct answer.

1. Have you tried to graph the word problem? Sometimes that will give you ideas! You know from reading, that there are certain points known. The line segment will begin at 0 weeks, owing $70, and end in 10 weeks, owing $0. You can use the formula for figuring slope with the 2 points, (0,70) and (70,0) After you have the slope, you can write the linear equation easily since you know the y intercept ($) is (0,70).
Start with a graph to comprehend the situation.

2. 3. These both use the point-slope formula. (you have a point, and the slope) On #3, the slope is the digit in front of the x . . . in this problem, it is the understood digit 1.

4. First you need to figure the slope using the 2 points given. There should be a formula in your book (I dislike typing formulas on the computer). After you have the slope, you can figure the equation using the slope and either one of the points given.

Hint! Most books have a handy chapter summary at the end of each chapter. I have my students copy it down and have it handy for the exercises. Very useful and keeps from having to flip all over finding equations.

Good luck!

Answer 2

1. Ok, y is the balance on the loan (in other words, the amount you pay) w is the number of weeks. You need to set up a formula using w, y and 7$. If you pay 7 dollars a week, the amount of money you pay (y) depends on how many weeks you pay for (w) so, y(money payed)=7 times w (howlong you pay for). So if you pay for 10 weeks, 7X10=70 dollars payed.

Answer 3

For increasing cubic binomials the overall formula is as follows: (a + b) ^ 3 = a^3 + 3*a^2*b^a million + 3*a^a million*b^2 + b^3 on your case, a is x and b is -y^5 So (x - y^5)^3 = x^3 + 3*x^2*(-y^5)^a million + 3*x^a million*(-y^5)^2 + (-y^5)^3 Simplified: =x^3 - 3x^2*y^5 + 3x*y^10 - y^15 :D

Answer 4

This should explain things at a reasonable pace.
http://www.wtamu.edu/academic/anns/mps/math/mathlab/int_algebra/int_alg_tut16_eqline.htm

Answer 5

2. use the equatuon y-y1=m(x-x1) where y1=0 and x1=3