i would subtract 7 and divide by 4;
4x + 7 = 15
4x = 8
x = 2
So first find a common denominator which is 100 in this question. Then change 5/10 into a denominator of 100 which is 50/100 you don't have to change 9/100 because it has a denominator of 100. So then add the fractions and the answer is 59/100
Answer:
It's letter C
Step-by-step explanation:
Answer:
Step-by-step explanation:
Using the addition formulae for cosine
cos(x ± y) = cosxcosy ∓ sinxsiny
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cos(120 + x) = cos120cosx - sin120sinx
= - cos60cosx - sin60sinx
= - cosx - sinx
squaring to obtain cos² (120 + x)
= cos²x + sinxcosx + sin²x
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cos(120 - x) = cos120cosx + sin120sinx
= -cos60cosx + sin60sinx
= - cosx + sinx
squaring to obtain cos²(120 - x)
= cos²x - sinxcosx + sin²x
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Putting it all together
cos²x + cos²x + sinxcosx + sin²x + cos²x - sinxcosx + sin²x
= cos²x + cos²x + sin²x
= cos²x + sin²x
= (cos²x + sin²x) =