<span>78.6 is a decimal number, you must name it with the whole part first and then the decimal part as part of tenths, hundredths or what it corresponds. In this case the whole part is 78 and the decimal part is 6/10 which is 6 tenths. Then, the number in words is sevety eight and six tenths.</span>
Answer: None
Step-by-step explanation:
y=0 and y=-5 don't have any solutions. When you ask if a pair of equations have a solution, that means there is an intersection of the equations. The 2 equations will meet somewhere, and that is the solution. To find the solution, you set the equations equal to each other.
0≠-5
It is obvious that 0 and -5 are not equal to each other. Therefore, there is no solution. Also, y=0 and y=-5 are horizontal lines that are parallel to each other. They will never meet, which means there will be no intersection. No intersection means no solutions.
First we use sin(a+b)= sinacosb+sinbcosa
and cos(a+b)=cosa cosb -sinasinb
tan(x+pi/2)= sin(x+pi/2) / cos(x+pi/2)
and sin(x+pi/2) = sinxcospi/2 + sinpi/2cosx =cosx,
<span>cos(x+pi/2) = cosxcospi/2- sinxsinpi/2= - sinx,
</span> because <span>cospi/2 =0, </span>and <span>sinpi/2=1
</span><span>=tan(x+pi/2)= sin(x+pi/2) / cos(x+pi/2)= cosx / -sinx = -1/tanx = -cotx
</span>from where <span>tan(x+pi/2)=-cotx</span>
Plug them in:
x + 5y = 18
x - 3y = 10
F. (1,13)
G. (13,1)
H. (-2,4)
J. (-2,-4)
1 + 5*13 = 18 is obliviously not true so that takes out the first option.
13 + 5*1 = 18 : This is true but we have to check the next one.
13 - 3*1 = 10 : This is also true so we know this is the answer. We don't really need to check the other 2 but u can if u want to.
Hope that helped :) <span />
equation for a circle is ( x - h )^2 + ( y - k )^2 = r^2,
so in first box - h
in second box - k
after equal to box = r²