Question

Select the best possible first step to solving the system by first eliminating the y variable. 4x − 5y = 4 3x + 2y = −20

Answer 1

Hey


Given equations :-

4x - 5y = 4

3x + 2y = - 20

For eliminating y , we have to multiply eq ( i ) by 2 and we have to multiply eq ( ii ) by 5 .


So ,

new equations :-

8x - 10y = 8

15x + 10y = - 100


=> 8x + 15 x = 8 - 100

=> 23x = -92


=> x = -93 / 23

=> x = - 4 .

So ,

putting the value of x in eq ( i ) ,

we get ,

3 ( - 4 ) + 2 y = - 20

=> - 12 + 2y = -20

=> 2y = - 20 + 12

=> 2y = -8

=> y = -8 / 2

=> y = - 4 .


thanks :)

Answer 2

--- 4x-5y=4, 3x+2y=-20
---2(4x-5y=4) and 5(3x+2y=-20)
---after that add the equations
15x+10y=-100
8x-10y=8
---23x=-92
---x=-4, is the ans
hope it helped!!