Answer:
Marco's age is 7 years old
Step-by-step explanation:
Let
x ----> Marco's age
y ----> Paolo's age
we know that
---->
----> equation A
----> equation B
substitute equation A in equation B


Solve the quadratic equation
The formula to solve a quadratic equation of the form
is equal to

in this problem we have

so

substitute in the formula





Remember that the solution cannot be a negative number
so
The solution is x=7
therefore
Marco's age is 7 years old
Answer: The answer to your first question would be A. 1. This is simply because anything raised to the power of 0 is 1 no matter what. The answer to your second question would be B. 1, for the same reason as above, anything to the power of 0 is 1. Hope this helped and make sure to remember that rule, it is important and easy to remember!
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:
1. x > 20
3. r > 4
5. x > 10
7. r < 8
11. x > 27
13. x < 40
(#7-13 had the greater than and less than symbol underlined)