The right answer is B.
The first step to answering this question is combining all like terms.
A. 2x + 2 + 2x + 3x - 8
The like terms in this expression are the x terms and the constants
So, what you would do is combine all of the x terms and combine all of the constants
(2x + 2x +3x) + (2 - 8)
7x - 6
B. 4 + 7x - 2
In this expression, you would combine all of the constants
7x + (4 - 2)
7x + 2
C. -2 + 5x + 2x - 4
For this expression, you would again, combine all of the x terms and all of the constants.
-2 + 5x + 2x - 4
(5x + 2x) + (-2 - 4)
7x - 6
D. 8x - x - 6
For this expression, you would combine all of the x terms
8x - x - 6
(8x - x) - 6
7x - 6
Now let's look at all of the new answer choices:
A. 7x - 6
B. 7x + 2
C. 7x - 6
D. 7x - 6
The question is asking you to find the one expression that's different. The only different one is B, so that's the answer.
Given:
t1 = 3.6 h
t2 = 4.5 h
x = speed of boat
y = speed of water
Required:
a) Expression of distance traveled with moving water with 3.6h
Expression of distance traveled with moving water with 4.5h
b) Solve for y
c) Percent of boat's speed is the water current
Solution:
Working formula: distance = velocity*time
a) For travelling downstream, we get the equation
d = (x +y)*3.6
For travelling upstream, we get the equation
d = (x-y)*4.5
b) Setting the distance as equal for travelling upstream or downstream, we arrive at the equation of
(x+y)*3.6 = (x-y)*4.5
3.6x + 3.6y = 4.5x - 4.5y
8.1y =0.9x
y = x/9
c) percentage = 1/9*100% = 11.1%
<em>ANSWERS: a) d = (x+y)*36; d = (x-y)*4.5
</em> <em>b) y = x/9
</em> <em>c) 11.1%</em>
The second condition tells you that

is half the size of

, so

, which could be rewritten in several ways. In standard form, that would be

.
Answer:
A
Step-by-step explanation:
(x-4)^2 = x^2 -4x -4x + (-4)*(-4)
= x^2-8x+16 as required
Answer:
Divide the 1st equation by 2
a + 2c = 19
Divide the 2nd equation by 3
a + c = 13.5
Subtract the 1st equation and the 2nd equation
c = 5.5
Substituting back into the 2nd equation will give:
a + 5.5 = 13.5
a = 8
Step-by-step explanation: