Sin (A + B) = sin A cos B + cos A Sin B
<span>Cos (A - B) = cos A cos B + sin A sin B </span>
<span>=> (SinACosB+ CosASinB) (CosACosB +SinASinB) </span>
<span>=>SinACosACos^2B+Sin^2ACosBSinB+Cos^2A... </span>
<span>=>SinACosA(Cos^2B+Sin^2B) +SinBCosB(Sin^2A+Cos^2A) </span>
<span>we know that Sin^2+Cos^2=1 </span>
<span>=>SinACosA(1)+SinBCosB(1) </span>
<span>=SinACosA+SinBCosB </span>
<span>Proved
</span>
Answer : B
x^2-9x+14
Lets factor 
We find out two factors whose product is +14 and sum is -9
Two factors are -2 and -7, we split the middle term -9x using -2 and -7

Group first two terms and last two terms
Then factor out GCF from each term



so x-2 is one of the factor
The expression that represents the amount that was not paid off is 
<u>Solution:</u>
Given, In 1995, the federal government paid off one-third of its debt. If the original amount of the debt was $ 4.920,000,000,000
We have to find which expression represents the amount that was not paid off
Now, we know that, amount that is not paid off = total debt – paid amount


Hence the expression and value of debt amount that is not paid off is found
Answer:
Step-by-step explanation:
it equals -19