Question

11x+15y+23 and 7x-2y-20=0 solve class 10 ch 3​

Answer 1

Step-by-step explanation:

Let's solve it through elimination method,

11x+15y+23=0-----1

7x-2y-20=0--------2

for this method to work we must equalize both variable, that is, we must multiply the equation to have equal variables to eliminate

I'll show you what I mean

Let's choose the variable y and make it 30

11x+15y+23=0 (×2 to the whole eq. )

22x+30y+46=0-----3

7x-2y-20=0 (×15 to the whole eq.)

105x-30y-300=0-----4

now since it is +30y and -30y we can just add it

adding 3 and 4 we get,

105x-30y-300=0

– 22x+30y+46=0

------------------------------

127x+0-254=0

now, 127x =254

x = 254/127 = 2

x = 2

Now

putting x = 2 in eq.2

(arbitrarily chosen you can put in any eq., I chose 2 because less calculation is required)

7(2) - 2y = 20

14 - 2y = 20

-2y = 20 - 14 = 6

y = -6/2 = -3

Therefore, x = 2 and y = -3

and you can check it by substituting the values in eq.1 and eq.2

Hope you understood it........All the best.