M= 2/7. I am not sure if it will put it in fraction form, but M=two sevenths.
Answer:
he got 20% wrong
he got a B
Step-by-step explanation:
Use the addition and subtraction theorem:
sin (A + B) = sin A + cos B
sin (A - B) = sin A - cos B
From there it's just a matter of simplification.
sin A cos B = 1/2 [ sin (A + B) + sin (A - B) ]
sin A cos B = 1/2 [ sin A cos B + cos A sin B + sin (A - B) ]
sin A cos B = 1/2 [ sin A cos B + cos A sin B + sin A cos B - cos A sin B ]
sin A cos B = 1/2 [ 2 sin A cos B ]
sin A cos B = sin A cos B
For the first one multiply each term by the LCM of 4 and 6, which is 12:-
15x -36 = 2y..................(1)
and second multiply by 5:-
2x + y = 9..............(2)
solving:-
from equation (2) y = 9-2x, substitute in equation (1):-
15x - 36 = 2(9-2x) = 18 - 4x
19x = 54
x = 54/19 = 2.84
so y = 9 - 2(2.84) = 3.32
The formula is <span>base × height / 2
So 8.7 x 15.6=135.72 / 2= 67.86
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