Answer:
1 4p= 32
2 17g
3 176 + 5
4 3x or x/3 (not too sure)
I would recommend "Introduction to Linear Algebra," by Gilbert Strang. It is a compact but very helpful textbook reference written by a well-known MIT professor. There is a corresponding online MIT course that is free, so that's a bonus. I am currently using it to study linear algebra with no class or previous experience, and I think it does a solid job of explaining things. Each section in the book has a set of questions for you to work through, and answers to selected questions appear in an appendix at the end of the book.
Hope this helps!
Answer:
x: work a woman can do in 1 day
y: work a girl can do in 1 day
Then
2x + 7y =1/4
4x + 4y =1/3
4x + 14y =2/4 (1)
4x + 4y =1/3 (2)
=> Let (1) - (2), 10y =2/4-1/3 <=>10y = 1/6 <=> y = 1/(6x10) = 1/60 (work)
=> From (2),4x = 1/3 - 4x1/60 => 4x = 16/60 => x = 4/60 (work)
=> 1 day, a woman and a girl can do: 1/60+4/60 = 5/60 =1/12 (work)
Then, the day required for a woman and a girl to complete work: 12 days
Answer:
Step-by-step explanation:
Let p represent cost of each drink.
We have been given that the medium pizza costs two times as much as one drink, so the cost of medium pizza would be 
.
We are also told that the large pizza costs three times as much as one drink, so the cost of la pizza would be 
.
We have been given that Mary wants to buy one large pizza, one medium pizza, and three drinks.
Since the cost of one drink is p, so cost of 3 three drinks would be .
The total cost of one large pizza, one medium pizza, and three drinks would be 
Mary started with $30, so amount left after all of her purchases would be 30 minus total cost of all purchases.
Therefore, Mary will have dollars left after making all of her purchases.
