Answer
$(-5,6)$ is a solution,
$(0,5)$ is not a solution,
$(10,-3)$ is a solution.
Work Step by Step
An ordered pair (a,b) is a solution of an equation in x and y if,
substituting a for x and b for y,
we obtain an equation that holds true.
Another way of stating this is that (a,b) satisfies the equation.
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$(x,y)=(-5,6)$
$3(-5)+5(6)=15$
$-15+30=15 \qquad $.... true, a solution
$(x,y)=(0,5)$
$3(0)+5(5)=15$
$0+25=15 \qquad $.... false, not a solution
$(x,y)=(10,-3)$
$3(10)+5(-3)=15$
$30-15=15 \qquad \qquad $.... true, a solution
