Answer:
ez
Step-by-step explanation:
Answer:
216 cookies
Step-by-step explanation:
From the question,
Let the total cookies in the first place be x cookies.
Their ratio = 5:12:9
Total = 5+12+9 = 26.
Weiming share = (5/26)x = 5x/26
If weiming sold 28 cookies
⇒ (5x/26)-28
⇒ (5x-728)/28
Hence Weiming new share = (5x-728)/28 cookies
The new ratio is 1:8:6
The total cookies becomes = x-28
Therefore,
(1/15)(x-28) = (5x-728)/28
(x-28)/15 = (5x-728)/28
Crossmultiply
28(x-28) = 15(5x-728)
28x-784 = 75x-10920
Collect like terms
28x-75x = -10920+784
-47x = -10136
x = -10136/-47
x = 215.7
x ≈ 216 cookies
Answer:
9: 89°
Step-by-step explanation:
Inside of a triangle is 180, so 180-39-52=89
I'm sorry I can't answer 10 for you
Answer:
11. 78
12. 4x² - 3x - 1
Step-by-step explanation:
11. Sum of n whole numbers = ½(n² + n)
Multiply
½*n² + ½*n
= n²/2 + n/2
To find the sum of the first 12 whole number, substitute 12 for n into the equation.
= 12²/2 + 12/2
= 144/2 + 12/2
= 72 + 6
= 78
12. Area of trapezoid = ½(a + b)*h
Where,
a = 5x - 4
b = 3x + 2
h = x + 1
Area = ½(5x - 4 + 3x + 2)*(x + 1)
Area = ½(8x - 2)*(x + 1)
Area = ½[8x(x + 1) -2(x + 1)]
= ½[8x² + 8x - 2x - 2]
Add like terms
= ½(8x² - 6x - 2)
= ½(8x²) - ½(6x) - ½(2)
= 4x² - 3x - 1
