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:
Step-by-step explanation:
Look at the picture.
The formula of an area of a triangle:
<em>b</em><em> - base</em>
<em>h</em><em> - height</em>
<em />
We need a length of a height.
Use the Pythagorean theorem:
We have:
Substitute:
<em>subtract 25 from both sides</em>
Calculate the area:
X=hours of plan A
y=hours of plan B
wed: 5x+6y=12
thu: 3x+2y=6
so
5x+6y=12 and
3x+2y=6
we can eliminate y's by multiplying 2nd equation by -3 and adding to first equation
-9x-6y=-18
<u>5x+6y=12 +</u>
-4x+0y=-6
-4x=-6
divid both sides by -4
x=-6/-4
x=3/2
x=1.5
sub back
3x+2y=6
3(1.5)+2y=6
4.5+2y=6
2y=1.5
y=0.75
Plan A=1.5 hours
Plan B=0.75 hours
