Posted by Sue on Monday, November 26, 2012 at 1:46pm.
if 5 times the first number plus 3 times the second number equals 47 and 10 times the first number minus 4 times the second number equals 54, what are the numbers?
please explain the steps
algebra - Steve, Monday, November 26, 2012 at 2:35pm
5x + 3y = 47
10x - 4y = 54
5x = 47 - 3y, so 10x = 94-6y, thus
10x-4y = 94-6y - 4y = 54
-10y = -40
so, x = 7
multiply the first equation by 4 and the 2nd by 3
20x+12y = 188
30x-12y = 162
add them, and the y's go away:
50x = 350
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