Answer:
cos 78⁰.
Step-by-step explanation:
Use cos 2A = cos^2 A - sin^2 A
so cos^2 39 - sin^2 39 = cos (2*39) = cos 78.
3x+4y=12 is Linear.
y-1/2x+6 is Linear.
y=4x^2 is nonlinear.
y+2=|4| is linear.
y+6=4x is linear.
In order to tell whether an equation is linear or not, you have to first see if there is any variable^2 or more than ^1. If that is the case, it isn't linear. For example the equation x^2=4 or y^5=100 isn't linear. It also isn't linear if the equation is divided by X or Y.For example the equation 1/x=1 isn't linear or 1/y^2=5 isn't linear.
A question is also linear if you can write it in the form y=mx+b , 'm' meaning the slope of the equation and 'b' meaning the y-intercept of the equation.
The correct answer to your question is 20x+25
Answer:
25 pounds
Step-by-step explanation:
Let us assume that initially, 1 pound of whole chicken costs x.
So, initially 20 pounds of whole chicken costs 20x.
Now, the price is reduced by 20%.
That means that 1 pound of whole chicken now costs ![x[1-\frac{20}{100} ]=0.8x](https://tex.z-dn.net/?f=x%5B1-%5Cfrac%7B20%7D%7B100%7D%20%5D%3D0.8x)
Therefore, with a 0.8x amount of money, we can now purchase 1 pound of the whole chicken.
Hence, with a 20x amount of money, we can now purchase 
pounds of the whole chicken.
A(n) = a(0) x (1/5)^(n)
Where (n) is the term number and a(0) is the first term
For example,
a(1) = 25(1/5)
= 5
a(2) = 25(1/5)²
= 1
And so on
