Answer:
Step-by-step explanation:
First of all, let's rewrite the first one after dividing both sides by 2.
Now, let's pick one you want to eliminate.
<u>Eliminating x:</u> Let's multiply the first one by 4, the second by 3, and subtract one from the other. Rest is simply solving an equation in one variable
<u>Eliminating y:</u> Let's multiply the first by 5, the second by 2, and add them together. Rest is simply solving an equation in one variable
Answer:
x= -2-√11. or. x= -2 + √11
Step-by-step explanation:
solving quadratic equation by completing the square
x^2+4x-7=0
x^2+4x=7
x^2+4x + (4/2)^2=7 + (4/2)^2 ( adding (1/2 coefficient of x)^2 on both sides
x^2+4x + 4=7 + 4
x^2+4x + 4=11. factorize(x^2+4x + 4) into (x + 2)^2
(x + 2)^2=11
√(x + 2)^2= + - √11
x + 2 = + - √11
there are two different solution .
x + 2 = -√11. or x + 2 = + √11.
x= -2-√11. or. x= -2 + √11.
2 - 3i is just another of writing (2, -3) in the cartesian plane, the 2-3i however is using the "imaginary axis" for the imaginary plane, is all however the imaginary axis is simply the equivalent of the y-axis. Likewise 9+21i is just (9,21), so let's just use the distance formula.
![\bf ~~~~~~~~~~~~\textit{distance between 2 points} \\\\ (\stackrel{x_1}{2}~,~\stackrel{y_1}{-3})\qquad (\stackrel{x_2}{9}~,~\stackrel{y_2}{21})\qquad \qquad d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2} \\\\\\ d=\sqrt{[9-2]^2+[21-(-3)]^2}\implies d=\sqrt{(9-2)^2+(21+3)^2} \\\\\\ d=\sqrt{7^2+24^2}\implies d=\sqrt{49+576}\implies d=\sqrt{625}\implies d=25](https://tex.z-dn.net/?f=%5Cbf%20~~~~~~~~~~~~%5Ctextit%7Bdistance%20between%202%20points%7D%20%5C%5C%5C%5C%20%28%5Cstackrel%7Bx_1%7D%7B2%7D~%2C~%5Cstackrel%7By_1%7D%7B-3%7D%29%5Cqquad%20%28%5Cstackrel%7Bx_2%7D%7B9%7D~%2C~%5Cstackrel%7By_2%7D%7B21%7D%29%5Cqquad%20%5Cqquad%20d%20%3D%20%5Csqrt%7B%28%20x_2-%20x_1%29%5E2%20%2B%20%28%20y_2-%20y_1%29%5E2%7D%20%5C%5C%5C%5C%5C%5C%20d%3D%5Csqrt%7B%5B9-2%5D%5E2%2B%5B21-%28-3%29%5D%5E2%7D%5Cimplies%20d%3D%5Csqrt%7B%289-2%29%5E2%2B%2821%2B3%29%5E2%7D%20%5C%5C%5C%5C%5C%5C%20d%3D%5Csqrt%7B7%5E2%2B24%5E2%7D%5Cimplies%20d%3D%5Csqrt%7B49%2B576%7D%5Cimplies%20d%3D%5Csqrt%7B625%7D%5Cimplies%20d%3D25)
Answer:
Step-by-step explanation:
Use Subtraction
1. Subtract
x+2y=7
3x-2y=-3
-------------
4x+0y=4 SIMPLIFY 4x=4
2. DIVIDE
4x=4
x=1
Substitute that into either of the original equations to get x=1, y=3
