So you will need to solve for x and y before evaluating 2x+y....

2x-y=9, y=2x-9 now this will make 4x^2-y^2=171 become:

4x^2-(2x-9)^2=171

4x^2-(4x^2-36x+81)=171

36x-81=171

36x=252

x=7, now we can use 2x-y=9 to solve for y...

2(7)-y=9

14-y=9

-y=-5

y=5

now we know that x=7 and y=5, 2x+y becomes:

2(7)+5

14+5

19

8 0

4 years ago

Hiow do you solve 3+3j=10+3j

vodomira [7]

No solution! Hope this helped

6 0

3 years ago

Using the equation in the previous problem calculate how long of a massage jaiden can have is she has approximately $180 the equ

irakobra [83]

180=-2x+30
x=-75

i think this is what we’re supposed to do

7 0

3 years ago

Find the measure of ∠C to the nearest degree.

Alisiya [41]

Well, sine is $\bf sin(\theta)=\cfrac{opposite}{hypotenuse}$ ,

but from the angle C, the opposite side, the one facing it off, is the side
AB, and we dunno what the side AB is

however, we know the hypotenuse is 8, and the adjacent side is 7,

and is right-triangle, thus, let us use the pythagorean theorem,

$\bf c^2=a^2+b^2\implies \sqrt{c^2-a^2}=b\qquad 
\begin{cases}
c=hypotenuse\\
a=adjacent\\
b=opposite
\end{cases}
\\\\
thus
\\\\
\sqrt{8^2-7^2}=b=AB$

now, that we know what the opposite side is, that is AB, then
we can find the sine of angle C $\bf sin(\theta)=\cfrac{opposite}{hypotenuse}\implies sin(C)=\cfrac{\overline{AB}}{\overline{BC}}$

3 0

4 years ago

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