<span>The Greenland ice sheet is a vast body of ice covering 1,710,000 square kilometers, roughly 80% of the surface of Greenland. It is the second largest ice body in the world, after the Antarctic ice sheet.</span><span />
To solve this problem, we need to set-up algebraic expression. First, use variables to represent the number of beads.
Let: x = number of Xavier's beads
y = number of Y<span>aozhou's beads
z = number of Zara's beads
</span>It is important to note that since we have three unknowns, we should also have three independent equations. <span>Based on the given statements, we have the following three equations:
(1) x + y = 438
(2) x + z = 204
(3) y = 3z
Substitute y in terms of z in equation (1). Then multiply equation (2) with -1.
x + 3z = 438
-(x + z = 204)
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2z = 234
z = 117
From equation (3),
y = 3(117) = 351
Using equation (1),
x = 438 - 351 = 87
Thus, Xavier had 87 beads.</span>
