Alg3.1.7

Solve the equations by eliminating y in $3x-y=3,7x+2y=20\,$

Given $3x-y=3,7x+2y=20\,$

Equating the coefficients of y in both the equations,

Multiplying the first one by 2

$6x-2y=6,7x+2y=20\,$

Adding both,we get

$(6x-2y-6)+(7x+2y-20)=0,13x-26=0,x=2\,$

Substituting the value in the first given equation,we get

$3(2)-y=3,-y=-3,y=3\,$

Therefore,the solution is $x=2,y=3\,$