Question

Solve by elimination
9x^2 + y^2 = 85
2x^2 - 3y^2 = 6

Answer 1

Mutliply 1st eq with 3

Answer 2

What do you get?

Answer 3

So 1st equ. is 27x^3+ 3y^2 = 225

Answer 4

2x^2 + 27x^3 = 231

Answer 5

27x^3 o_O?

Answer 6

opps 29x^2

Answer 7

the same power

Answer 8

Now divide 231 with 29

Answer 9

7.96 take the square root 2.822

Answer 10

Wait you mutilpied wrong...

Answer 11

9x^2 + y^2 = 85
2x^2 - 3y^2 = 6

First eq mutiply by 3 will be 27x^2+3y^2=255

Answer 12

So,
27x^2+3y^2=255
2x^2 - 3y^2 = 6
===========
29x^2=261

divide 261 with 29
x^2=9

Answer 13

i see ...9 take the square root x=3

Answer 14

Ya!

Answer 15

substitute the x value to find y right?

Answer 16

Yes! in the ORIGINAL second eq i.e
2x^2 - 3y^2 = 6

Answer 17

y = square root of 10

Answer 18

2(9)-3y^2=6
18-3y^2=6
subract 18 both sides
18-3y^2=6
-18 -18
=========
-3y^2=-12
y^2=-12/-3
y^2=4

Answer 19

y=2