Solve the following simultaneous equations: 3x + 5y = -4 and -2x + 3y = 9
Label the equations 1 and 2 We want to make it so the x are the same number - therefore we have to find a common multiple of 2 and 3 - this is 6 Therefore the equations turn into: 1) 6x + 10y = -8 2) -6x + 9y = 27 Add together: 19y = 19 Therefore y = 1 Plug back into equation 1: 3x + 5 = -4 Therefore x = -3 Check with equation 2: -2(-3) + 3(1) = 9
KP
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