Question 1065929
s+v = 130 subtract s from both sides: v = 130-s
Next:
4.50s+6.50v = 617 substitute for v:
4.50s+6.50(130-s) = 617
= 4.50s+845-6.50s = 617
= -2s = -230 divide both sides by -2, and remember -/- = +
s = 115
115 students showed up.