X, y - the numbers

The numbers add to 9 and multiply to -70.
$x+y=9 \\
xy=-70 \\ \\
y=9-x \\
xy=-70 \\ \\
\hbox{substitute 9-x for y in the second equation:} \\
x(9-x)=-70 \\
9x-x^2=-70 \\
-x^2+9x+70=0 \\
-x^2+14x-5x+70=0 \\
-x(x-14)-5(x-14)=0 \\
(-x-5)(x-14)=0 \\
-x-5=0 \ \lor \ x-14=0 \\
x=-5 \ \lor \ x=14 \\ \\
y=9-x \\
y=9-(-5) \ \lor \ y=9-14 \\
y=14 \ \lor \ y=-5 \\ \\
(x,y)=(-5,14) \hbox{ or } (x,y)=(14,-5)$

The numbers are -5 and 14.

4 0

3 years ago

Solve for x The value of x is

Varvara68 [4.7K]

Answer:

7x+19 = 11x-89

-19. -19

7x= 11x-108

-11x -11x

-4x=-108

x=27

8 0

3 years ago

Describe how you would find

cestrela7 [59]

Well if it’s volume just multiply all the numbers together so 8x5= 40x3=120 so the answer would be 120

8 0

2 years ago

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