Question

3x+2y-z+5w=20
y=2z-3w
z=w+1
2w=8
Solve this system.

Answer 1

Explanation:

or , w = 8/2

or , w = 4

i think this is the answer

Answer 2

Start from the last equation:

2w = 8 ⇒ w = 4

z = w + 1 ⇒ z = 4 + 1 ⇒ z = 5

y = 2z - 3w ⇒ y = 2•5 - 3•4 ⇒ y = -2

3x + 2y - z + 5w = 20 ⇒ 3x + 2•(-2) - 5 + 5•4 = 20

⇒ 3x = 9 ⇒ x = 3