Answer:
a = 8.5
Step-by-step explanation:
Take the second equation and flip it around so the y on the left ends up on the right and the 4x on the right ends up on the left. This makes all negatives positive and all positives negative. -4x + 12 = y
Then add the first equation to the second equation
4x +12 = -7y
<u>-4x + 12 </u>=<u> y </u> this eliminates the x's
<u>24</u> = -<u> 6y</u> then divide by - 6
- 6 - 6
- 4 = y<u>
</u>So if you know that y = negative 4, you can substitute into either equation. I pick the second one because I am a lazy person.
-y + 12 = 4 x
-(-4) + 12 = 4 x combine your numbers<u>
</u> <u> 16 </u> = <u>4 x </u> then divide by 4<u>
</u> 4 = x
So your solution is: x = 4 and y = -4 or this is also written (4, -4)
Does that work for you?
There are two triangles that are 15cm in height and 10cm in width so you do 15 times 10 which is 150 then divided it by 2 because it a triangle to get 75 then because there is 2 you then multiply it by 2 again and you get 150
That is a 30 60 90 triangle.
Read about those here: http://www.1728.org/trig2.htm
Answer:
Step-by-step explanation: