If X + Y = 7, Y + Z = 5, and Z + W = 8, then XY + WZ + XZ + YW is:

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Official Explanation

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To solve for XY + WZ + XZ + YW, we first need to express each variable in terms of one variable. From the equations, we have: 1) X + Y = 7, so Y = 7 - X. 2) Y + Z = 5, substituting Y gives us (7 - X) + Z = 5, which simplifies to Z = X - 2. 3) Z + W = 8, substituting Z gives us (X - 2) + W = 8, which simplifies to W = 10 - X. Now we can express XY, WZ, XZ, and YW: XY =…

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Comments

ashrithApr 14, 2025

Amazing

SritamApr 26, 2025

Thanks for sharingThank you for sharing!!thanks for sharing

WaheedJan 11, 2025

thanks for taking time to upload it!

TarekMar 17, 2025

finally understood this

JustinMay 4, 2024

thanks

What this question tests

What it tests

Your ability to manipulate linear and quadratic expressions, substitute unknowns, and solve equations under time pressure.

Common trap

Losing a sign when moving terms across the equals sign, or dividing both sides by a variable that could equal zero.