Answer: approximately 29 feet
Explanation: You need to find a tree so that the angle of elevation from the end of the shadow to top of the tree is 40 degrees.
The length of the shadow is an adjacent side and is 35.
The height of the tree is the opposite side. You could use X.
Tan ratio = opposite/adjacent
tan(40) = x/35
x = 35*tan(40) =29.37
Amount of money collected in the 2-day fundraiser is represented by the following equations:
- 12x + 4y = 152 .................. (i)
- 32x + 12y = 420 .................. (ii)
where x is the cost of a chicken lunch and y is the cost of a vegetarian lunch
Multiplying (i) with 3 and subtracting it from (ii)
36x + 12y - (32x + 12y) = 456 - 420
⇒ 4x = 36
⇒ x = 9
Put value of x in (i)
⇒ 12 × 9 + 4y = 152
⇒ 108 + 4y = 152
⇒ 4y = 44
⇒ y = 11
Hence, cost of the vegetarian meal is 11.
Comment.
9A
Let's use (a) as an example. What number is in front of the x inside be brackets? If I gave you the choice of 1,2,3,4,5 which number is it out of those 5?
If you chose 5, you have the second best answer. You are reading outside the brackets. Not what we need.
If you choose 1, you are well on your way. There is a 1 beside the x.
Now go to the outside of the brackets. What's in front of the x? 1,2,3,4,5.. There is only one number you can choose. It's a 5. So the result outside the brackets is 5x. How did 1x become 5x? You had to put a 5 on the blank to the left of the brackets..
5(5 + x) = 5x + ___ What goes on the line to the right of 5x? Rule whatever you do to one side of a plus sign inside the brackets, you must do to the other side of the plus sign.
It becomes 5*5
So the blank is filled with 25. And here's the answer.
5(5 + x) = 5x + 25 <<<< answer..
Stop don't do anything more. 5x and 25 are not like terms. They don't mix
9B
Let's make this one brief so that you have something to do. What did you multiply 5 by to get 10? You should answer 2.
2(x + 5) = ___ x + 10
What you do on one side of the plus sign, you must do on the other. So what's in front of the x on the right?
2(x + 5) = 2x + 10 <<<< answer
