If w(w - 1) = 42 and z(z - 1) = 42, and if w z, what is the value of

Question

If w(w - 1) = 42 and z(z - 1) = 42, and if w > z, what is the value of w + z ?

(A) -1

(B) 0

(C) 1

(D) 12

(E) 13

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paragw · Answer

Here's my solution:

vasu1104 · Answer

w(w-1) =42
w^2 - w -42 = 0
(w-7)(w+6) = 0
w = 7 , -6

z(z-1) = 42
z^2-z -42 = 0
(z-7)(z+6) =0
z= 7,-6

since w>z
w=7
z= -6

w+z = 7-6 = 1

option c

Bunuel · Answer

GMATNinja Video Solution:

https://www.youtube.com/watch?v=cmpDVLHzT3w

PrakharD · Answer

w(w-1) = 42 -(1)
z(z-1) = 42 -(2)

From (1)&(2)
w(w-1) = z(z-1)
w2-w = z2-z
w2-z2 = w-z
(w-z)(w+z) = w-z
=> w+z = 1

TheAdmissionHub · Answer

w(w-1) = 42

w^2-w-42=0

(w-7) * (w+6) = 0

w=7  and  w=-6

Since the equations are the same, we have the same results also for z:  z=7  and   z=-6

Given that  w>z   →  w=7, z=-6  →  w+z=1

Answer: C

If w(w - 1) = 42 and z(z - 1) = 42, and if w > z, what is the value of