Question

30 POINTS Solve by the linear combination method.

4x – 5y = –18
3x + 2y = –2




(–2, 7)


(–2, 2)


(–1, 3)


(3, –1)

Answer 1

Explanation:

Solve by the linear combination method.

4x – 5y = –18

3x + 2y = –2

i selected the incorrect answer and the correct answer is bellow.

Selected Answer:

Incorrect

(–2, 7)

Correct Answer:

Correct

(–2, 2)

Answer 2

4x – 5y = –18 (1st)
3x + 2y = –2 (2nd)

Multiply 1st equation by 2 and 2nd equation by 5

4x – 5y = –18 (1st) (mul. 2)
3x + 2y = –2 (2nd) (mul. 5)

8x - 10y = - 36
15x + 10y = - 10
-----------------------add
23x = - 46
x = -2

3x + 2y = –2
3(-2) + 2y = –2
-6 + 2y = -2
2y = 4
y = 2

(-2,2)

answer

(–2, 2)