Solve the simultaneous equations 2x+3y=-3 3x-2y=28

1 answer:

4 0

$\left \{ {\big{ 2x+3y=-3\ /\cdot2} \atop\big {3x-2y=28\ /\cdot3 }} \right.\\\\ \left \{ {\big{ 4x+6y=-6} \atop\big {9x-6y=84 }} \right.\\---------\\4x+9x=-6+84\\\\13x=78\ /:13\\\\x=6\\\\2x+3y=-3\ \ \ \ \Rightarrow\ \ \ 2\cdot6+3y=-3\ \ \ \Rightarrow\ \ \ 3y=-3-12\\\\3y=-15\ /:3\\\\c=-5\\\\Ans.\ \left \{ {{x=6} \atop {y=-5}} \right.$

You might be interested in

Simplify 8+7/8x−1−1/2x.

Katena32 [7]

Answer:

7 + 3/8x

Step-by-step explanation:

8+7/8x−1−1/2x.

Combine like terms

8-1 + 7/8x -1/2x

7 + 7/8x -1/2x

Get a common denominator

7 + 7/8x -4/8x

7 + 3/8x

7 0

3 years ago

An example of a "golden rectangle” has a length equal to x units and a width equal to x – 1 units. Its area is 1 square unit. Wh

Llana [10]

Area=length times width

area=1=x times (x-1)

1=x(x-1)
1=x^2-x
0=x^2-x-1
using quadratic formula
for
0=ax^2+bx+c
$x= \frac{-b+/- \sqrt{b^2-4ac} }{2a}$
for
0=1x^2-1x-1
a=1
b=-1
c=-1

$x= \frac{-(-1)+/- \sqrt{(-1)^2-4(1)(-1)} }{2(1)}$
$x= \frac{1+/- \sqrt{1+4} }{2}$
$x= \frac{1+/- \sqrt{5} }{2}$

$x= \frac{1+ \sqrt{5} }{2}$ or $x= \frac{1- \sqrt{5} }{2}$
the 2nd one will be negative so we reject that because we can't have negative lengths

so
$x= \frac{1+ \sqrt{5} }{2}$
the length is $\frac{1+ \sqrt{5} }{2}$