Answer:
Identity is verified.
Step-by-step explanation:
We have to verify the identity 
To prove any identity we always prove one side(either left hand side or right hand side) of the equation equal to the other side.
In this identity we take the left hand side first

(as we know cos(a+b) = cosa×cosb-sina×sinb)


= - sinx ( Right hand side)
Hence identity is proved.
Answer:
3. 4 meters
6. wrong, it should be 7000 meters
7. 2 dm > 10 cm
8. 30 cm = 3 dm
9. 6 km > 5000 m
10. 8 m < 90 dm
Step-by-step explanation:
__________
84.15-1.8*8
Order of Operations says to add and subtract before you multiply, so simplify the expression to: 82.35*8, which is 658.8
Answer:
x=(10,0)
y=(0,4)
Step-by-step explanation:
Rewrite the equation so it is 5y=2x-20
Multiply both sides by 5
Then figure out the equation and you get the x intercept
Then put 10 into your new equation in the x spot and thats how you get y
Hope this helps:)
If my explaining is not good you can also use Math_way and it shows you all th steps too.
Answer:
18.37 is the answer so it should be 18.4
Step-by-step explanation: