algebra
posted by Jackster on .
Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this.
5x – 7y = 25.5
2x + 10y = 9

The plan is to get the coefficients of either the x's or the y's to be the same or opposite
I will go for the x's to be the same ...
1st equation times (2) : > 10x + 14y = 51
2nd equation times (5): > 10x  50y = 45
subtract them ....
64y = 96
y = 96/64 = 3/2
sub into original 2nd
2x + 10(3/2) = 9
2x = 9 + 15 = 6
x = 3