Answer:
Then, a=-1 and b=-1
Step-by-step explanation:
We need to solve the following system of equations using the adition method:
2a+3b=-1 (i)
3a+5b=-2 (ii)
First, we multiply the equation (i) by -3 and the equation (ii) by 2, so we get:
-6a-9b=3
6a+10b=-4
Adding the two equations we have:
-6a-9b=3
6a+10b=-4
--------------------------
0 + b = -1
Then b=-1. Now, let's substitute the value of b into equation (i):
2a+3b=-1
2a + 3(-1) = -1
2a -3 = -1
2a = 2
a = 1
Then, a=-1 and b=-1
Answer:
287 books
Step-by-step explanation
there was already 239 books. when the problem mentoins that Mary ADDS MORE books to the shelf, the operation is addition.
239+48=287
You use the equation Ax^2 + Bx + C to solve this equation.
The answer is 25.
I hope this helps :D
I imagine that not everyone that visited Becky’s Store spent a lot of time and money there. If she surveys only those that did, this is not a representative sample because she is leaving out other customers. She would have no one in her sample that represents customers who spent a lot of time but no money, or little time and no money or even little time and a lot of money. These are just some examples but clearly her sample is biased.