Example:
This suggests two solutions,
and
.
However, upon plugging these solutions back into the equation, you get
which checks out, but
does not because
is defined only for
(assuming you're looking for real solutions only). So, we call
an extraneous solution, and the complete solution set (over the real numbers) is
.
Set up your two equations:
<span>9x+7y=53 </span>
<span>3x+5y=25 </span>
<span>X=cost per pound of jelly bean </span>
<span>Y=cost per pound of trail mix </span>
<span>Multiply the second equation by (-3): </span>
<span>-9x-15y=-75 </span>
<span>+ 9x+7y=53 <---- copy first equation and add them </span>
<span>—————— </span>
<span>0x-8y=-22 </span>
<span>Then solve for y: </span>
<span>Y=2.76 this is your cost per pound of trail mix. </span>
<span>Then plug y back in to one of the original equations and solve for x: </span>
<span>3x+7(2.75)=25 </span>
<span>X=3.75 this is you cost per pound of jelly beans</span>
Answer:
C. c^2=a^2+b^2-2abcos(90°)
Step-by-step explanation:
This is the law of cosine.
I hope this helps you
13x-11x=-25-15
2x=-40
x=-20
5t-5t=7+5
0=12 false