The formula is
A=p (1+r)^t
A future value?
P present value 675
R interest rate 0.09
T time 7 years
A=675×(1+0.09)^(7)=1,233.93
Answer:
Student B is correct
Student A failed to distribute -4 and -6 when opening the brackets in the first step
Step-by-step explanation:
The solution Student A gave was:
2x - 4(3x + 6) = -6(2x + 1) - 4
2x - 12x + 6 = -12x + 1 - 4
-10x + 6 = -12x - 3
2x = -9
x = -4 _1 2 ( -4 1/2)
The solution Student B gave was:
2x - 4(3x + 6) = -6(2x + 1) - 4
2x - 12x - 24 = -12x - 6 - 4
-10x - 24 = -12x - 10
2x = 14
x = 7
Student B is correct.
Explanation of the error:
Student A failed to distribute -4 and -6 when opening the brackets in the first step.
That is,
2x - 4(3x + 6) = -6(2x + 1) - 4
To open this bracket, we will distribute, -4 and -6 so that we get
2x (-4 × 3x) + (-4 × +6) = (-6×2x) + (-6 × +1) - 4
Then we will get
2x -12x -24 = -12x -6 -4
Adding the like terms
-10x - 24 = -12x - 10
Collecting like terms
-10x + 12x = -10 + 24
∴ 2x = 14
x = 14 / 2
Hence,
x = 7
Here’s my work to your question!
2x + 3y = 45
x + y = 10......y = 10 - x
2x + 3(10 - x) = 45
2x + 30 - 3x = 45
-x + 30 = 45
-x = 45 - 30
-x = 15
x = -15 <====
and y = 25
3b^2 - x = -9b^2
x = 3b^2 +9b^2
x = 12b^2
3b^2 -12b^2 = -9b^2
hope this will help you
