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