Question

What are the solutions of the system 7x + 3y = -3 and y = -2 x ?

(-1, 0) and (-8, 3)
(0, -1) and (3, -8)
(-1, 0) and (0, -1)
(-8, 3) and (3, -8)

Answer 1

I am assuming that the second equation is
`y = -2^x`. In that case, the correct answers are (0, -1) and (3, -8).

Answer 2

(0, -1) and (3, -8)

Explanation:

7x + 3y = -3 and y = -2^x

LEts check with each option

(-1, 0) and (-8, 3)

y=-2^x , plug in x=-1

y= -2^-1 =-1/2 is not equal to 0

(0, -1) and (3, -8), plug in (0,-1)

y=-2^x = -2^0 = -1, so (0,-1) satisfies the equation y=-2^x

LEts check with equation 7x+3y = -3

7(0)+3y =-3

3y=-3 so y =-1

Hence (0,-1) satisfies the both equation

LEts check with (3,-8)

y=-2^x= -2^3= -8

7x+3y=-3

7(3)+ 3y=-3

21 +3y=-3

3y=-24 so y = -8

(3,-8) also satisfies both equations