Answer
$$x=5$$
Work Step by Step
$y_{1}=10x + 6$ equation 1
$y_{2}=12x - 7$ equation 2
$y_{1}$ exceeds $y_{2}$ by 3 --> $y_{1}$ = $y_{2}+3$ equation 3
Substitute equations 1 & 2 to equation 3:
$$(10x + 6)=(12x - 7)+3$$
Remove the parentheses:
$$10x + 6=12x - 7+3 $$ $$10x + 6=12x - 4$$
Subtract $6$ from both sides:
$$10x + 6-6=12x - 4-6$$ $$10x=12x-10$$
Subtract $12x$ from both sides:
$$10x-12x=12x-12x-10$$ $$-2x=-10$$
Divide both sides by $-2$:
$$x=5$$