5(3y)-y=75 -> 15y-y=75 -> 14y= 75 -> y= 75/14
3(75/14)=x -> x= 225/14 and y= 75/14
I'm completely wrong but i tried
Answer:
Take x = 10.2 in. or x = 10 in.
Step-by-step explanation:
Given :
Length = (2x+3) in.
Breadth = x in.
Also, the Area of Rectangle = 240 sq in.
We know that,
Area of Rectangle = length x breadth
240 = (2x+3) x
2x² + 3x = 240
2x² + 3x - 240 = 0
Solving 2x²+3x-240 = 0 by the Quadratic Formula .
According to the Quadratic Formula, x , the solution for Ax2+Bx+C = 0 , where A, B and C are numbers, often called coefficients, is given by :
- B ± √ B²-4AC
x = ————————
2A
In our case, A = 2
B = 3
C = -240
Accordingly, B² - 4AC = 9 - (-1920) = 1929
Applying the quadratic formula :
-3 ± √ 1929
x = ——————
4
√ 1929 , rounded to 4 decimal digits, is 43.9204
So now we are looking at:
x = ( -3 ± 43.920 ) / 4
Two real solutions:
x =(-3+√1929)/4=10.230 ≈ 10
or
x =(-3-√1929)/4=-11.730
We'll take x = +ve value for calculation of length and breadth.
Therefore,
Length = [2(10.2) + 3 ]
L = 23.4 in.
Breadth = 10.2 in.
OR
Length = [2(10) + 3]
L = 23 in.
Breadth = 10 in.
Answer:
-1.44285714286
Step-by-step explanation:
Answer:
- 9 nickels
- 12 dimes
- 6 quarters
Step-by-step explanation:
We are given relations between the number of each kind of coin and the number of quarters. So, it is convenient to write an equation in terms of the number of quarters.
Let q represent the number of quarters. The number of nickels is 3 more than that, so is (q+3). The number of dimes is 6 more than the number of quarters, so is (q+6). The total value of the coins, in cents, is ...
5(q +3) +10(q +6) +25q = 315
40q +75 = 315 . . . . . . . . . . . . . . collect terms
40q = 240 . . . . . . . . . subtract 75
q = 6 . . . . . . . . . divide by 40
q +3 = 9 . . . . number of nickels
q +6 = 12 . . . number of dimes
There are 9 nickels, 12 dimes, and 6 quarters in the collection.
