Question

Which system is equivalent to y = -2x , y = x-2 ?

Answer 1

The given system of equation can be solved if x = 2/3 and y = -4/3.

So we need to find another system which can be solved by these values.

From the given 4 options lets find out which can be solved by x = 3/2 and y = -4/3

1.

y = -2y^2 -2 , x = y - 2

lets put the value of y here

y = -2(16/9)-2 = -32/9-2= -50/ 9

So not an equivalent equation.

2.

y = -2y^2 + 2 , x = y + 2

y = -2(16/9)+2=-32/9+2=-14/9

So not an equivalent system.

3.

y = -2y^2 - 8y - 8 , x = y + 2

y = -2(16/9)-8(-4/3)-8 = -32/9+32/3-8=64/9-8=-8/9

So not an equivalent system.

4.

y = -2y^2 + 8y - 8 , x = y -2

y = -2(16/9)+8(-4/3)-8=-32/9-32/3-8=-128/9-8=-22.22

So this is not an equivalent equation too