Answer:
cos (12+10) = cos (22)
Step-by-step explanation:
Cos 12* cos 10* - sin 12* sin 10*
Appling the trig identity: cos (a + b) = cos a.cos b - sin a.sin b
inputing the values of a and b
cos (12 + 10) = cos 12cos 10 - sin 12sin 10 = cos (22)
1/2*(-1/7) = - (1*1)/(2*7)= - 1/14
(+)*(-) = (-)
Answer : - 1/14
<span>2x+3y=3
</span><span>-3x-2y=8
3y=3-2x
-2y = 8+3x
y = 1 - 2x/3
y = -4 - 3x/2
</span>1 - 2x/3 = -4 - 3x/2
5 = - 3x/2 + 2x/3
5 = -9x/6 + 4x/6
5 = -5x/6
x = 5 * 6/-5
x = -6
No plug it in.
<span>2x+3y=3 ; x = -6
-12 + 3y = 3
3y=3+12
3y=15
y = 5
So </span>x = -6 and y = 5
