1)

If 2x + y = 17; y + 2z = 15 and x + y = 9, then what is the value of 4x + 3y + z ?


A) 41

B) 43

C) 42

D) 55

Answer:

Option C

Explanation:

Given,
2x+7 = 17----(1)
y+2z = 15----(2)
x+y = 9----(3)
Subtracting equations (3) - (1) we get
x = 8
Put value x in (3), we get y = 1
Put value of y in (2), we get 2z = 14 i.e, z = 7
$\therefore$ 4x+3y+z = $(4 \times 8) +(3 \times 1)+7=42$