A^2 = b^2 + c^2 - 2bc cos a
= 11^2 + 5^2 - 2*5*11 cos 40
= 7.86 to 2 DP's
to find the remaining angles use the sine rule:-
a / sin A = b / sin B so
7.857/ sin 40 = 11 / sin B
sin B = 11 sin40 / 7.857 = 0.8999
<B = 64 degrees
so <C = 180 - 64-40 = 76 degrees
(-5,-1) would be the coordinates since the only thing we’re changing by moving west is that we’re subtracting from the x value. Therefore, 2-7 is -5 so we get -5,-1
3x^2 + 9x + 6 = 0
3x^2 + 3x + 6x + 6 = 0
3x(x + 1) + 6(x + 1) = 0
(3x + 6)(x + 1) = 0
3x + 6 = 0 and x + 1 = 0
3x = -6 and x = -1
x = -2 and x = -1