Which expressions can be represented by the model?
1 answer:
You might be interested in
Let b equal the speed of the boat in still water.
Let c equal the speed of the current.
Going downstream, we can write the equation:
which can be rearranged to:
3b + 3c = 120 ............(1)
Going upstream, we can write the equation:
which can be rearranged to:
4b - 4c = 120 .............(2)
Multiplying equation (1) by 4, and multiplying equation (2) by 3 we get:
12b + 12c = 480 ........(3)
12b - 12c = 360 .........(4)
Adding equations (3) and (4) results in the following equation:
24b = 840
Let c equal the speed of the current.
Going downstream, we can write the equation:
which can be rearranged to:
3b + 3c = 120 ............(1)
Going upstream, we can write the equation:
which can be rearranged to:
4b - 4c = 120 .............(2)
Multiplying equation (1) by 4, and multiplying equation (2) by 3 we get:
12b + 12c = 480 ........(3)
12b - 12c = 360 .........(4)
Adding equations (3) and (4) results in the following equation:
24b = 840
Answer:
Sabrina bought 3 pounds of bananas.
Step-by-step explanation:
Given equations are:
a + b = 8 Eqn 1
0.95a + 1.10b = 8.05 Eqn 2
As we have to find the number of pounds of bananas bought, we will eliminate the variable a from the equation.
Multiplying Eqn 1 by 0.95
0.95(a+b=8)
0.95a+0.95b=7.60 Eqn 3
Subtracting Eqn 3 from Eqn 2
(0.95a+1.10b)-(0.95a+0.95b)=8.05-7.60
0.95a+1.10b-0.95a-0.95b=0.45
0.15b = 0.45
Dividing both sides by 0.15
Hence,
Sabrina bought 3 pounds of bananas.