Question

For which system of inequalities is (3,-7) a solution?

A. x + y < -4
3x + 2y < -5

B. x + y ≤ -4
3x + 2y < -5

C. x + y < -4
3x + 2y ≤ -5

D. x + y ≤ -4
3x + 2y ≤ -5

Answer 1

D) x + y ≤ -4

3x + 2y ≤ -5

Explanation:

Step(i):-

we will choose the system of inequalities

x + y ≤ -4

3x + 2y ≤ -5

x + y = -4 ...(i)

3x + 2y = -5..(ii)

Multiply equation (i) with '3'

3x + 3y = -12

3x + 2 y = -5

- - +

0 + y = -7

Step(ii):-

Substitute y = -7 in equation (i)

x + y = -4

x - 7 = -4

x = -4 + 7

x = 3

The solution of the given inequalities is ( 3, -7)